Features: 1.Precise incisions and interfaces ensure perfect fit, suitable for mounting position and easy to install. 2.The product uses high quality materials, effectively avoid corrosion and wear out, and durable. 3.Professional chip set provides superior performance in the system. 4.Easy to operate, anti-aging, and extended service life. 5.The DIP switch makes it easier to directly adjust the gain of the post amplifier, better promotes greater damping of the speaker. Specifications: Material: ABS Color: As picture shown Size: Approx. 8x5x2cm/3.1x0.2x0.8in Power: 2.1 interface DC 8~25V power supply Audio input: various versions of Bluetooth connection stereo input, using CSR8635 Bluetooth chip, Bluetooth V4.0, extremely high software compatibility Output impedance: 8 Ω (can drive 4, 6, 8, 16 Ω impedance speakers) Output power: enough to add the front stage 5532 output power Packing List: 1 x Module 1、Precise incisions and interfaces ensure perfect fit, suitable for mounting position and easy to install. 2、The product uses high quality materials, effectively avoid corrosion and wear out, and durable. 3、Professional chip set provides superior performance in the system. 4、Easy to operate, anti-aging, and extended service life. 5、The DIP switch makes it easier to directly adjust the gain of the post amplifier, better promotes greater damping of the speaker.