[High-Fidelity Mono Amplifier] Experience superior sound with the ZK-1001B Bluetooth amplifier board, featuring a 100W mono output for passive speakers (20-100W, 3-8Ω). Equipped with a TPA3116D2 chip for less than 0.3% distortion and advanced AAC BT decoding, this amp ensures crisp audio reproduction. [True Wireless Stereo (TWS) Functionality] Leverage the power of two ZK-1001B units with TWS BOX mode to create a stereo sound setup. This feature allows for seamless connection and synchronization of two independent Bluetooth amplifier boards, enhancing your audio experience with true stereo quality. [Versatile Control Knob] Manage your audio settings effortlessly with a multifunctional control knob. Adjust volume by rotating, play or pause with a single click, skip tracks with a double click, and toggle TWS mode with three clicks. A long press powers the unit on or off, offering comprehensive control in one interface. [Multiple Input Options & Bluetooth 5.1] This compact amplifier supports various inputs including AUX, USB flash drive, and USB sound card, alongside Bluetooth 5.1 connectivity for a stable, low-latency connection up to 15m/49ft. Easily connect a wide range of devices to enhance your listening experience. [Robust Protection Features] Designed for durability, the ZK-1001B amplifier board measures 89 x 45 x 20mm and includes multiple protection mechanisms such as over-voltage, under-voltage, over-heat, and short-circuit protection. Encased to safeguard against damage, ensuring longevity and reliable performance. Shipping in disassembled, requires assembly before use. Color:Black Material:Plastic+Metal Package Contents: 2 * Mini Bluetooth audio amplifier board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.