1. The energy storage capacitor is increased, 4700ufx2+470uf, the sound from the stereo and especially the subwoofer is stronger.2. Output LC filtering, the use of film capacitors has better filtering effect, no sound is emitted from the inductor, and the waveform restoration is better.3. The volume of both stereo and subwoofer can be adjusted separately, and the adjustment range is wider. Using a new high-level Bluetooth chip, the parsed audio delay is smaller and clearer.4. Supports the Bluetooth pairing function. After using the TWS function, two sets of amplifiers can be paired to become stereo. Connect to APP, can support remote firmware upgrade or firmware refresh, easy to upgrade and perfect product function.5. Added -down circuit to reduce sound. Increase the heat sink, the heat dissipation effect is better.Model: TB22chip:TPA3116D2Input Mode: BluetoothWork Voltage: DC 12V-24V(Above 2A)Channel: 2.1 Stereo OutputBluetooth version: Bluetooth 5.1Bluetooth transmission distance: 10m(If you need to go further, please connect the antenna yourself)MAX Output: 50W x 2 +100Wtype:Amplifier Boardsize: 121 x 100 x 26mmMaterial: plasticcolour: blackPackage Contents:1 x TB22 Bluetooth Amplifier BoardOnly 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.