... prompt, ease of use. Support dual-network of both PSTN landline and GSM mobile network, provide redundancy for extra stability. 2 ... , triple-band, quad-band GSM/GPRS industrial graded module, stable and reliable. Alarm accessories, Other products, Welcome to inquiry ... motorcycles, shops and house.Especially, our RF Transmitter/Receiver module used extensively in the garage, shutter and automatic door, ...