The Remote Transmitter & Receiver Board is a scientific experiment-assisted developmental toy. It stimulates student's development through scientific experiments and provides a realistic environment with its design. Features - - Material:Copper - Size: 3.50X3.00X1.00cm/1.38X1.18X0.39in (transmitter) - Size: 2.40X1.90X1.00cm/0.94X0.75X0.39in (receiving board) - Transmitter voltage: DC3V - Receiving board voltage: DC3-4.5V - Mounting hole: applicable to M2.3/M2.5 screws - Remote control distance: about 3-5 meters - Wiring method: The red, black wires are connected to the power supply, and the yellow and are connected to the motor. - Adopting from copper material, which is lighweight, with and good workmanship. - Stimulates children's scientific curiosity with the diy RC Module. Captivating children's interest in electric toys. - It is a DIY Electrical Experiment that can provide opportunities to learn scientific principles. - Great DIY model for kids interests for learning of science, developing children structure imagination, exercising. - Stimulate your child's interest in learning and lay the foundation for learning. Suitable for hands easily assemble. Package list: 4 x circuit boards 4 x antennas