369DRONE PRO Trinity Arm SET for MIROKU PRO Trinity Frame Review
A $25 set of four PRO Trinity arms (listed as 4mm) plus mounting screws, aimed at owners of a MIROKU PRO frame or of a PRO Trinity who want arms for 3-point fastening. The listing says the set converts the frame to PRO Trinity; the frame itself is not included.

Our verdict
A set for someone who owns a MIROKU PRO frame, or an existing PRO Trinity, and wants four arms with mounting screws, since the listing says it converts the frame or serves as spare arms. Look elsewhere if you need the frame itself, arms for a different frame or a stated arm weight. The main caveat is that the listing says the arms are ultra-light and sharpen throttle response and cornering, and no weight or test figure backs those statements.
- Best for
- Someone who owns a MIROKU PRO frame, or an existing PRO Trinity, and wants a four-arm set with mounting screws.
- Skip if
- You need the frame itself, arms for a different frame or a stated arm weight.
Listed at $25 as a single option, the PRO Trinity Arm SET is named for the MIROKU PRO Trinity Frame and holds four arms listed as 4mm plus mounting screws for 3-point fastening. The listing says swapping the set into a MIROKU PRO frame converts it to PRO Trinity, and that it also works as spare or replacement arms for existing PRO Trinity owners. It states that the frame itself and TPU parts are not included.
Options and pricing
There is one option, a single variant at $25, so the page offers no choice of arm thickness or quantity. The contents list reads PRO Trinity Arm 4mm x4 and mounting screws for 3-point fastening. The listing gives no screw size and no screw count, and it says the set holds arms and screws only, so the frame itself and TPU parts are not part of it.
How it compares
The TUF Trinity Arm SET for MIROKU TUF Trinity Frame is also $25, but its title and Fits row name the MIROKU TUF Trinity Frame, so it is for a different frame and does not replace this set. The PRO Trinity Arm 4mm for MIROKU PRO Trinity Frame is listed at $6 with Size: 4mm and Material: carbon, while this $25 listing is a set of four arms with mounting screws. The two pages describe different things, so the data does not show that either one replaces the other.
Shipping and processing
- Processing. The store's shipping policy says every order, including orders placed through the Shop app, ships from its warehouse in Japan and is dispatched within 1-3 business days after payment is confirmed (checked 2026-11-11).
- Shipping cost. The policy gives a flat 800 JPY inside Japan and 5,000 JPY to eligible countries for parcels up to 2 kg, and gives no rate for heavier parcels. It does not list the eligible countries; the store's country selector offers the United States, Canada, the United Kingdom, Australia and New Zealand, and the terms of service reserve the right to limit sales to any region, so the checkout is the final test. At the rate the store used for US prices when we looked (about 0.00642 USD per JPY), 5,000 JPY is about $32; the checkout shows the exact amount.
- Price against shipping. This listing costs $25, less than the flat international shipping fee above. The policy prices shipping per parcel up to 2 kg, so what an order of several small parts pays depends on how the store packs it, and the pages do not say.
- Duties and taxes. The policy says import duties, taxes and customs clearance fees are not included in the price or the shipping cost, are charged to the recipient by the carrier (it names DHL, FedEx and Japan Post) and are outside the store's control. It declares the full value of the goods on customs papers and cannot mark a parcel as a gift or declare less. A parcel held for unpaid duties is not delivered, and if the carrier sends it back the return shipping is deducted from any refund.
- Tracking. A tracking number is issued once the parcel ships. For international parcels it can take a few days to show up, and it can change when the parcel is handed from one carrier to another.
Returns and warranty
- Returns. The store's refund policy gives 30 days after receiving an item to request a return. The item must be in the condition received, unworn or unused, with tags and in its original packaging, and you need the receipt or proof of purchase. Use the contact page first: if the return is accepted the store sends a return shipping label and instructions, and items sent back without a request are not accepted. The policy does not say who pays the return shipping on a change-of-mind return. Refunds go to the original payment method within 10 business days after the store has received and inspected the item (checked 2026-11-11).
- Not returnable. The refund policy lists custom products (special orders and personalized items), perishable goods, personal care goods, hazardous materials, flammable liquids and gases, sale items and gift cards. The legal notice, which is in Japanese, adds made-to-order items, digital downloads once downloaded, and goods whose value was lost through the buyer's use or modification. For an exchange the policy says to return the item and, once the return is accepted, buy the new one separately.
- Damaged or wrong items. The refund policy asks buyers to inspect an order on arrival and to contact the store at once about a defective, damaged or wrong item so that it can evaluate the issue and make it right. The legal notice says the store exchanges or refunds such an item at its own cost.
- Warranty. The shipping policy, refund policy and legal notice describe no warranty, and we found no warranty page. The terms of service say products are provided 'as is' except as the store expressly states, disclaim warranties, and are governed by Japanese law. Many of the parts this store sells are made by other brands; nothing says whether the store or the maker handles a fault that appears after the item has been in use (checked 2026-11-11).
Before you buy
369DRONE describes itself as an FPV racing drone brand from Japan. Its About page says the founder, Daichi Sakakibara, spent over a decade as a test driver at Toyota Motor Corporation and builds products with experience from racing. These are the store's own statements (checked 2026-11-11).
The store is in Japan and quotes yen. The price on this page is its United States dollar price as of 2026-11-11; the store converts at its own rate, which moves, and a visitor in another country can see a different amount or currency.
The legal notice, written in Japanese, says the products are meant for FPV drone racing and hobby use, asks buyers to follow the Aviation Act, the Radio Act and other laws, and says the store takes no responsibility for damage caused by use that breaks the law. Those are Japan's laws. We have not checked what applies where you live and we do not say whether this product can be flown or operated legally in your country.
The English refund policy takes back items that are "unworn or unused", while the Japanese legal notice says, as we read it, unused and unopened, so check the condition rule with the store before opening the package. We have not read any independent review of this product or of the store.
What we liked
- The contents list is specific: PRO Trinity Arm 4mm x4 plus mounting screws for 3-point fastening
- Named for the MIROKU PRO Trinity Frame, and the listing says it also works as spare or replacement arms for existing PRO Trinity owners
- The listing says plainly what is left out: the frame itself and TPU parts
- A single option at $25, so there is no thickness or quantity to pick
Worth noting
- The listing calls the arms ultra-light but gives no weight for the set or for one arm
- No screw size or screw count is given for the mounting screws
- The spec row says TPU, while the text says TPU parts are not included and never names the arm material
- The listing says 3-point fastening adds rigidity and sharper throttle response and cornering, with no test or figure
Questions before you buy
Which frame is the PRO Trinity Arm SET listed for?
The title and the Fits row name the MIROKU PRO Trinity Frame. The listing adds that the set also works as spare or replacement arms for existing PRO Trinity owners, and that swapping it into a MIROKU PRO frame converts it to PRO Trinity.
What does the set contain?
The contents list names PRO Trinity Arm 4mm x4 and mounting screws for 3-point fastening. The listing says the set holds arms and screws only, so the frame itself and TPU parts are not included.
What does it cost and are there options?
The listing shows one variant at $25 and no choice of size.
Can I return it if I change my mind?
The refund policy gives 30 days after receipt to request a return of an unused item in its original packaging, with proof of purchase; contact the store first and wait for its return label. Custom products, sale items and gift cards cannot be returned, and the pages do not say who pays return shipping.
How long and how much to get it from Japan?
The shipping policy says the order ships from Japan and is dispatched in 1-3 business days after payment. International shipping to eligible countries is a flat 5,000 JPY for parcels up to 2 kg (about $32 at the store's US rate); the store's country selector lists the US, Canada, the UK, Australia and New Zealand.
Who pays import duties and taxes?
The recipient. The shipping policy says import duties, taxes and customs fees are not in the price or shipping cost, are collected by the carrier and cannot be predicted by the store. A parcel held for unpaid duties is not delivered, and return shipping is deducted from any refund if the carrier sends it back.
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- PRO Trinity Arm SET for MIROKU PRO Trinity Frame product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead November 11, 2026
- 369DRONE shipping policyShips from Japan, dispatched in 1-3 business days, flat international rate up to 2 kg, duties and taxes not included, trackingRead November 11, 2026
- 369DRONE refund policy30-day returns of unused items in original packaging, contact first, non-returnable items, refunds within 10 business daysRead November 11, 2026
- 369DRONE legal notice (in Japanese)Seller details, payment methods, delivery time, returns, digital files, and the notice to follow aviation and radio lawsRead November 11, 2026
- About 369DRONEThe brand's own account of its founder and design approach; marketing, not independent evidenceRead November 11, 2026
What we couldn’t verify
- The listing says the arms are ultra-light and that 3-point fastening adds rigidity and sharpens throttle response and cornering, but it gives no weight, test or figure, so we could not check these claims.
- The spec row lists TPU as the material, but the text says TPU parts are not included and never names the arm material, so the material is unconfirmed.
- We have not read any independent review of this product or of the store; the About page is the store's own account.
- The English refund policy takes back items that are unworn or unused, while the Japanese legal notice says unused and unopened; we could not tell which rule applies.
- The store's pages describe no warranty and its terms provide goods 'as is'; we could not tell who handles a fault that appears after use.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.


