1, 5 0 bluetooth version, transmission efficiency is higher, transmission distance is longer 2 Large size heat sink ensures efficient heat dissipation 3, potentiometer to adjust the volume, with a switch, easy to control the volume, very suitable for DIY speakers If it is a metal box, you need to draw out the bluetooth antenna 4 Copper DC connector is adopted to withst high current no heat 5 4470uF green gold capacitor guarantees the power storage capacity the continuous stable power supply is the premise of good sound quality 6 The DC head with cable can be compatible with the input power interface of this product Even if you don't have the DC head adapter or battery, you can connect it easily Adaption Supply Voltage: 5-24V (9V/12V/15V/18V/24V adapter, high power recommended high voltage)Power Supply Voltage: 12V------8hom speaker/24W (Left channel) and 24W (Right channel), 4 ohm speaker/40W and 40W,15V------8homs /32W and 32W, 4 ohm/greater than 60W and 60W,19V------8homs /64W and 64W, 4 ohm/greater than 80W and 80W,24V------8homs /72W and 72W, 4 ohm/greater than 100W and 100WParameter:Product Name:HIFI with filter 2X100W Bluetooth digital power amplifier boardModel: ZK-1002LChip Solution: domesticWith or Without Filter: YesAdapter Speaker: 50W-300W, 4 ohm-8 ohmNumber of Channels: Left right stereo (Stereo)Bluetooth Version: 5 0Bluetooth Transmission Distance: 15m(Without occlusion)Protection Mechanism: Overheating protection,Short Circuit protectioncolour:blackMaterial:Metal andpcPackage Contents:1 Bluetooth 5 0 Digital Amplifier Board1 shell1 screwdriver1 power cordNotes for use: the power switch on the board is stby switch, the machine is in stby state with low power consumption after the switch is turned off Tocompletely turn off the power or to remove the DC plug on the machine for a long time, it is ok Tip: To have enough output power if the audio input is sufficient the supply voltage/current is sufficient The power supply voltage is higher the relative power will be larger The speakers with different impedances will have different output power In the case of sufficient voltage current, the larger the ohms of the horn, the smaller the relative sound power Please pay attentionOnly the above package content, other products are not included Note: Light shooting 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