BAPI Wireless Duct 418 MHz Temperature Transmitters feature closed cell foam to seal the probe insertion hole and to absorb vibration.Mounting feet allow for easy installation directly to the wall of the duct.The Duct Units come with etched teflon leadwires, double encapsulated sensors and a watertight BAPI‑Box enclosure to withstand high humidity and condensation and perform under real world conditions.The units are available with probe lengths from 4" to 18" to accommodate most duct shapes and sizes.Custom probe lengths are also available.The Wireless Duct Temperature Transmitter measures the duct temperature and transmits the data through 418MHz RF to a receiver.It has an in‑building range of 100 feet and an estimated battery life of 8 years using two high‑capacity 3.6V lithium batteries with a transmit rate of about once every 20 seconds.Each transmitter has a unique address with built in error detection.Each variable sent by the transmitter is picked up by the receiver and converted by a BAPI Analog Output Module to a voltage, current or resistance signal which is sent to the controller