Features 1、The amplifier module is equipped with a terminal block and a DC 2.1mm socket, which is compatible with most laptop power ports. Can directly connect to wireless Bluetooth 5.0. and compatible with a variety of speakers. 2、The built in filter capacitor of this digital power amplifier module makes it available for processing sound signals. Knob potentiometer design, convenient to adjust power ON and OFF, V+ and V‑. 3、Two 20W, 30W or 50W power amplifier boards are equipped with various speakers (4 to 8 Ω), and support Bluetooth stereo audio input and AUX audio input. 4、Adopt acrylic protective shell design, with reverse connection protection, overvoltage protection, undervoltage protection, over temperature protection, short circuit protection. Self recovery overheating protection. 5、This bluetooth speaker power amplifier board has no POPs sound when powering on, skipping songs and pausing. It is widely used in refitting speakers, power amplifier equipment, and car Bluetooth equipment. Specification Item Type: Power Amplifier Board Material: PCB Purpose: Digital Power Amplifier Board Model: ZK-502L Bluetooth Version: 5.0 Input Method: Bluetooth Number Of Channels: Left and Right Dual Channels (stereo) Bluetooth Version: 5.0 (Unobstructed, Approx. 15m/49.2ft) Signal To Noise Ratio: >90 dB Adapted Speakers: 30W-200 W, 4Ω-8Ω 12V-8 Ω/12W+12W, 4 Ω/20W+20W 15V-8 Ω/18W+18W, 4 Ω/30W+30W 19V-8 Ω/32W+32W, 4 Ω/45W+45W 24V-8 Ω/38W+38W, 4 Ω/50W+50W Protection Mechanism: Self Recovery Overheating Protection, Self Recovery Short Circuit Protection Package List 1 x Power Amplifier Board 1 x Screwdriver 9 x Screw 4 x Brass Connecting Rod 2 x Acrylic Board 1 x Knob 1 x Cable