Robocraze 4CH 27/40 MHZ Remote Control Circuit PCB Transmitter Receiver DIY RC Car Robot Wiring: (1) start-up board: red line V + then positive power source, black line V-then negative power supply, ant then the antenna; (2) receiver board: the black line connected to the power supply is negative, the red line connected to the power supply is positive; R and L then motor, B and F line then motor. B and F output voltage more. (L)X(W): 5.7X3.8cm/2.24"X1.5"(appr.) Receiver Board Size:(L)X(W): 4.3X2.6cm/1.69"X1.02"(appr.) Features Brand New and high quality. Made of plastic and electronic Components material, durable and long life service. Suitable for toy model, remote control car, remote control boat. Can be used to control the direction of movement of the toy car like going forward or backward. Attention:only can use small power motor, such as 130 motor, high power motor can burn the board. Notice: Please allow 1-3mm error due to manual measurement and make sure you do not mind before ordering. Please understand that colors may exist chromatic aberration as the different placement of pictures. Package Included: 2 x 4CH Board (with screws accessories) 4 lines,2v-3.5v Receiving range about 10meter Connection method: Emission Plate: red V+ positive power supply, black wire V- negative power supply, ANT connect the antenna