Easy to use, nice range (using antenna on both), you can send strings (text) from one point to another. If you want to automate your house without pulling cables then this device will help you well. Wireless Transmitter Modules allow your for to wirelessly comunicate with other for arduinos, or with radio frequency (RF) controlled devices that operate in the same frequency (433Mhz in this case). Compatible with 434MHz RF transmitter and RF receiver This Radio Transmitter & Receiver pair is perfectly matched to allow you to control items from a distance up to 500 feet wirelessly! Product Type: MX-05V Working voltage: DC5V Quiescent current: 4MA Receiving frequency: 433.92MHZ Receiving sensitivity: -105DB External antenna: 32CM single core, wound into a spiral Transmitter technical parameters: Product Type: MX--03V Launch distance: 20-200 meters (voltage is different, the effect is different) Operating voltage: 3.5-12V Work: AM Transmission rate: 4KB / S Transmit power: 10mW Launch frequency: 433M External antenna: 25cm ordinary multi-core or single-core Pin arrangement from left to right: (DATA; VCC; GND) Remarks: VCC voltage and module voltage should be consistent, and to make the power filter; Antenna greatly affect the receiving effect of the module, the best access 1/4 wavelength antenna, generally using 50-ohm single-core wire, the length of the antenna 433M is about 17cm; The position of the antenna also affects the receiving effect of the module. When installing, the antenna should be as straight as possible, far away from the shielding body, high voltage and interference source. When using, the receiving frequency, decoding and oscillation resistance should match with the transmitting. Colour: green Material: PCB Size: receiver size: 30x14x7mm, transmitter size: size: 19x19mm Package Contents: 5 * Transmitters 5 * Receivers Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.