The KH-(2.4G)-K503-XJB is an electronic part with antennas manufactured by Kinghelm. It is RoHS compliant, meaning it does not contain any hazardous materials such as lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl and polybrominated diphenyl ether. It is a 2.4GHz wireless radio transmitter and receiver set with an internal patch antenna and external dipole antenna that is designed for long-range transmission and reception. This product is ideal for product development projects, wireless surveillance, remote control, and robotics. It can be used for wireless sensing, communication, and remote control applications with an operating range of up to 2 kilometers.