ION Security Products” MICA : [a] Composition Micro-processor, Micro-transmitter, Lithium Battery, Optimized Antenna for superior zone signal sar Specif Dimensions Dowel Package 0.33 inch deep by 0.75 inch diameter Power Source 340V Lithium Coin Cell Battery {CR1E20} Cavity Depth Fit 0.33 inch depth Transmit Range Typically »500 &, open air System Incompatibilities Sensors are compatible with current USC GE, HAL and 2616 wireless receivers. Please be sure to specify which system you require.