The pocket size transmitter F21-2S/D has a glass fiber structure with class IP65 protective enclosure. It is safe and operates accurately in temperature ranges of -35C to +85C. Providing more than 4.3 billion unique ID codes for general usage,this transmitter can be easily configured and tuned using windows based software. An extra shock resistance relay is available specifically for mobile devices operating in DC mode. It also operates at low power, utilizing 2 AA batteries that can last up to 4 months.