 Introducing the Geo CT Wireless Door Window Contact for the Geo Alarm, with 800 foot line of sight range, utilizing the encrypted 433 MHz frequency, with 5 years battery life using a CR2032 battery, low battery and tamper protection monitoring. This device operates in temperatures from 32 degrees to 122 degrees Fahrenheit. With small dimensions, only occupying 1.69 by 2.52 by 0.51 inches of space. Once again, ladies and gentlemen, introducing the Geo CT Wireless Door Window Contact for the Geo Alarm.