Linear dxt-42 keychain transmitter General Specifications ^ Dimensions: 2.25 in L x 1.25 in W x 0.48 in H (57 x 32 x 12 mm), excluding key ring eyelet^ Power: Two CR1616, CR1620, or DL1620 3V lithium cells (supplied)^ Current Consumption: 5 mA average while transmitting^ Battery Life: Three years (typical)^ Measured Range: 300 feet minimum in open air, four quadrants^ Number of Channels: DXT-41, one channel: DXT-42, three channels - left button, right button, both buttons simultaneously^ Operating Frequency: 315MHz Features Long-life button cell lithium batteries supplied. Up to 300 feet of range. Compatible Models DUAL-824 Supervised Wireless/Hardwire Security Panel DXSR-1504 Supervised 4-Channel Receiver DXSR-1508 Supervised 8-Channel Receiver PERS-2400A Personal Emergency Reporting Console, 16 Zone DVS-1200 Supervised Wireless Security Console DVS-2400 Supervised Wireless Security Console DXR-701 1-Channel Receiver DXR-702 2-Channel Receiver The Model DXT-42 2-Button, 3-Channel Key Ring Transmitter is a battery powered, portable, miniature transmitter designed for use with Linear's DX Format receivers. Each transmitter can be used in a limitless number of wireless remote control applications. Pressing a transmitter button sends a digitally coded wireless signal to its companion receiver. The transmitter buttons have a positive click feel. The digital DX code format features over a million possible codes. The DX transmitters are precoded at the factory to unique codes, so no field coding is required. Transmitters can send a signal for up to 10 seconds with each button activation. The DXT-42 is a two-button, three-code transmitter. Each button sends a unique code. Pressing both buttons together sends code three. Press button(s) for a minimum of two seconds to insure receiver activation.