4CH RC remote control 40MHz circuit PCB transmitter & receiver board Radio system for toy car

40MHZ 4CH Remote Controller Receiver Transmitter Board with Antenna for DIY RC Car Truck Accessories – Electronic frequency: 40MHZ – Material: Metal – Color: Green Size Chart: Receiver: Approx. 4 x 55mm/ 0.15 x 2.16inch Transmitter: Approx. 25 x 36.8mm/ 0.98 x 1.44inch Package Includes: 1 Piece Transmitter Board 1 Piece Receiver Board 2 Pieces Antenna