OE Audio CIEM 2Pin and MMCX Adapter Review

OE Audio's CIEM adapter is priced at $24.99 in every option. The title names 2Pin 0.78mm to MMCX and MMCX to 2Pin versions, and the options add Black and Clear colors and three 3.5mm versions. The page's spec section gives a PU body, a 3U-Gold-Plated connector, Mondolf Supreme soldering and a polyurethane injection process.

Specifications

Options and pricing

Six options are listed at $24.99 each. Black 2Pin to MMCX and Clear 2Pin to MMCX were sold out when the page was read, while Clear MMCX to 2Pin, Black MMCX to 3.5mm, Clear 2Pin to 3.5mm and Black 2pin to 3.5mm were orderable. The page text gives no length and no in-the-box list.

How it compares

The DD ddHiFi DJ44B/DJ44C Mark II adapter is $29.99 and is named a 4.4mm female to 2.5/3.5 male headphone adapter, so it changes plug sizes, a different job from the 2Pin and MMCX connections this OE Audio adapter names at $24.99. The SKW WG20-02C Car Aux Audio Cable starts From $24.99 and is named 3.5MM to 3.5MM. The OE Audio suits buyers joining 2Pin or MMCX connectors; the others suit plug-size changes or whole cables.

Shipping, returns and warranty

HiFiGO sells from hifigo.com and says every order leaves its warehouse in China, usually 1-3 business days after it is placed, and says its delivery times are estimates, not promises. Its shipping policy gives the United States 1-2 weeks (about 10 days on average) by Priority and 6-10 days by Premium, both with duties and taxes prepaid by the store; Canada 2-3 weeks; the United Kingdom 1-2 weeks; and Australia 10-15 days. Express couriers (DHL, UPS, FedEx) take 3-7 days, but then the buyer pays any duties and taxes. No shipping page names New Zealand, PO boxes are not accepted, and the free-shipping thresholds differ between the store's own pages, so check the cart. One of its two shipping pages adds that a lost parcel on an order above $50 gets only a 50% refund. A US buyer reported a $40 tariff charge in August 2025, after which HiFiGO said it had added a customs notice at checkout.

Read the return terms before you order. The homepage advertises 7-day returns. Both of HiFiGO's policy pages offer a 7-day dead-on-arrival cover (a replacement or a full refund, with the return postage refunded) and also describe 30-day returns, but a request made 7 to 30 days after delivery loses 30% of the MSRP as a restocking fee (10% more if the packaging is incomplete), plus shipping both ways and duties, and the FAQ on the same pages says there is no refund or exchange once 7 days have passed. One version recommends reselling an opened product locally. Custom IEMs and custom cables cannot be returned, no return address is published, and buyers describe sending items back to China.

Cables and adapters get three months of warranty from the order date, against one year for DACs, amps and IEMs; a note on the same page also excludes cables from returns for hygiene reasons, while the FAQ says a cable can come back in its original condition. HiFiGO decides between repair and replacement and the buyer pays the shipping. Claims go to [email protected], the only contact the store lists: its pages name no company, street address or phone.

On Trustpilot, HiFiGO had 4.6 out of 5 from 378 reviews when we checked on 2026-10-28 (91% five-star, 5% one-star), and it had replied to about 75% of negative reviews; Trustpilot notes the store has not invited customers to review recently. The one-star reviews mostly concern the short return window and the deductions on returns, items listed in stock that turned out back-ordered, slow email support and a tariff charge on a US delivery in 2025. HiFiGO says its products are genuine and come in the brands' retail packaging; it does not claim to be an authorized dealer.