AirFly Pro 2 vs Avantree Relay: Which Airplane Adapter Wins?

The Avantree Relay is the better airplane Bluetooth adapter for most travelers. It pairs with two sets of headphones, lasts up to 25 hours, has onboard volume controls, and supports the same useful transmitter codecs as the AirFly Pro 2. It also includes the two-prong airline adapter that Twelve South reserves for its more expensive Deluxe bundle.

The AirFly Pro 2 is the better choice only if you need receiver mode. That lets a phone send Bluetooth audio to a wired car stereo, speaker, or other AUX input. The Relay is a transmitter only.

On September 15, 2026, Avantree listed the Relay at $34.99 and Twelve South listed the AirFly Pro 2 at $59.99. That price gap is too large to ignore when their in-flight feature sets are so close.

AirFly Pro 2 vs Avantree Relay: The Quick Difference

Both adapters solve the same flight problem: they plug into a 3.5 mm seatback jack and send the audio to wireless headphones. Both can connect two headphone pairs for shared listening, both charge over USB-C, and both have a two-year manufacturer warranty.

The Relay is the flight-first value pick. Along with its lower list price, it includes a dual-prong airline adapter and gives you separate connection lights for the first and second headphones plus a four-level battery indicator.

The AirFly Pro 2 is the more flexible little audio tool. Its TX mode handles seatback entertainment, while RX mode sends Bluetooth audio from your phone or tablet into a wired AUX input. If you want one adapter for flights and an older car stereo, that extra mode can justify the higher price.

Shared Listening and Bluetooth Codecs

There is no meaningful winner for two-person listening. The AirFly Pro 2 has dedicated Pair 1 and Pair 2 buttons. The Relay uses one multifunction pairing button and separate indicators for each headphone connection. The controls differ, but both let two people hear the same seatback screen.

Their transmitter codec lists are also effectively tied: aptX Adaptive, aptX Low Latency, aptX HD, aptX, and SBC. The actual codec is the best option supported by both the adapter and the connected headphones, so an aptX logo does not guarantee low latency with every pair of earbuds.

That makes the Relay's lower price more important than small differences on a spec sheet. For ordinary in-flight use, neither product has a clear audio-format advantage.

Battery, Controls, and What Comes in the Box

Battery life is another tie. Avantree rates the Relay for up to 25 hours, while Twelve South rates the AirFly Pro 2 for more than 25 hours. Both manufacturers list a two-hour charge time over USB-C.

Both adapters put volume controls and battery indicators on the device. The AirFly Pro 2 adds dedicated pairing buttons and a TX/RX switch. The Relay keeps its controls simple with one main pairing button, volume buttons, two headphone-status lights, and four battery-level lights.

The box is where Avantree pulls ahead for flights. Its dual-prong adapter covers older airline sockets without another purchase. The regular AirFly Pro 2 includes the transmitter and charging cable, but not that airline adapter. If that accessory is why you are considering Twelve South's bundle, the AirFly Pro 2 vs Deluxe comparison explains exactly what the upgrade adds.

Which One Should You Buy?

Buy the Avantree Relay if your main job is getting seatback audio into one or two pairs of Bluetooth headphones. It handles that job, includes the useful airline adapter, and leaves a meaningful amount of money in your pocket.

Buy the AirFly Pro 2 if receiver mode is part of the plan. It is the better fit when the same adapter needs to work on a plane and then stream music from your phone into an older car stereo or wired speaker at your destination.

For more small fixes that make flights less annoying, see TrekSavvy's guide to travel gear that solves the worst parts of flying.

The Bottom Line

The Avantree Relay wins for most travelers. It matches the AirFly Pro 2 on dual-headphone listening, battery life, USB-C charging, volume controls, warranty, and transmitter codec support, then includes the two-prong airline adapter at a lower price.

Pay more for the AirFly Pro 2 only if you know you will use receiver mode. Otherwise, the Relay is the more complete flight kit and the better value.