This antenna was standard for the G2 Field and Pro Series transmitter and with the Pro Control receiver. It will fit all other Tri-Tronics transmitters with removable antennas by using the adaptor that is included with the purchase of the antenna. This is a direct replacement for the 7.5" antenna used on Sport, Pro and Field Series systems built prior to the G2. The 3.5" antenna is also a direct replacement and works with no loss of range. (1236000)