Check the listing for details. Linear ET-1B Wireless Emergency Transmitter. Color: Silver, Condition: New. Listed at 19.00 USD. Linear ET-1B Wireless Emergency Transmitter, a compact, single-channel portable signaling unit used as a panic button in security systems. Operation: Requires pressing both buttons simultaneously for a minimum of two seconds to activate the signal, preventing false alarms. Durability: The device is water-resistant and designed for reliability in various environments. Customization: It uses a standard digital format with 256 selectable codes to protect against inadvertent activation of nearby receivers. Accessories: The product includes an adjustable lanyard with a breakaway release for wearing around the neck or attaching to a keyring. Applications: Common uses include emergency notification for panic, intrusion, and system arm/disarm functions