Description: 100% and high quality. Made of material, durable, high performance. Great accessories for WPL MN RC Truck. All-in-One Functions: Awesome RC Sound System with many functions packed in one at very low price. It has very fine throttle control that you will like for low speed crawling! Receiver; ESC; Servo Control; Winch Control; Gear Shift; Sound Module; Light Control; Car 1 / Car 2 Switch; Low voltage protection; Support 2-3S; PWM output for External ESC; Auto Drag Brake at Low Gear; Low voltage protection: 2S - 6V; 3S - 11V ESC max supported current : 14A(under-load); Requires two AA batteries for remote(not included); What's in V3 vs V2; PWM output for external ESC; Added Auto Drag brake at Low Gear (manual braking at high gear); Improved/Fixed; Doubled the ESC amp output; Triple radio signal; Even better throttle modulation; Gear shift now starts at high gear; Not backward compatible with V2 Sound System. The set doesn't come with any plug/battery connector, you may use your own that fits. Doesn't work with the yellow color 6V 700mah Ni-CD battery. In case you're on single speed gear, gear shift button becomes the On/Off for Auto Drag Brake. Actual receiver may look a little different but function is the same. Pls Note: Pay attention to the positive and negative poles of the socket. The set does not contain lights, the lights need to be purchased separately. The receiver can be received by multiple remote controllers(it is 1 remote control and can be used with multiple receivers) Very Important: Pls note the '+' & "-" of the battery, otherwise, will burn the circute board! The battery need 7.4V lithium battery, full battery. Battery's discharger rate need at lease 15C. The circute board need to use this sound system radio, can't binding other mitter. A Series: Petrol Engine Sound/B Series: Crude Oil Truck Sound Colour: black Material: composite material Package Contents: 1 * remote control 1 * receiving board 1 * speaker 1 *