APTX & APTX LOW LATENCY SUPPORTED. Powered by premium CSR8670 chipset, TROND BT-DUO supports the latest Bluetooth V4.1, whereas most of others on Amazon are V4.0, V3.0 or even V2.1. With aptX, you can enjoy CD-quality sound wirelessly over Bluetooth connections with aptX-source devices like TV's, phones or tablets. With aptX Low Latency, you can now watch video while listening to wireless audio in a synchronized fashion and without any noticeable audio delay BLUETOOTH TRANSMITTER MODE (TX). TROND BT-DUO can transmit stereo audio wirelessly from your non-Bluetooth audio sources such as TV, MP3, CD player, PC, or Nintendo Switch/3DS to your Bluetooth-enabled headphones or speaker. This way, you can enjoy high quality music wirelessly, or listen to late night shows without disturbing your loved ones while they sleep. Please also order TROND TD-BH01 Over-Ear Bluetooth V 4.2 Headphones for the best low latency performance BLUETOOTH RECEIVER MODE (RX). Previously TROND BT-DUO only supported aptX LL & aptX in the transmitter mode, and we have just added aptX LL & aptX into the receiver mode as well. Now you don't have to pay high premium to get aptx LL-enabled wireless headphones or speakers; instead, your wired headphones or speakers can be easily turned into wireless audio devices with low latency