The Tri-Tronics Upland G2 is an electronic remote trainer and beeper that is a favorite among upland hunters, bird dog trainers that require a combination beeper and training collar. The unit has 6 continuous stimulation levels and 18 momentary levels, with a 1 mile range. The Upland G2 model is for use with 1- Dog. For the same series that is used for 1-3 dogs see, the Tri-Tronics Upland G2 EXP. (Additional EXP Extra Receiver/Beeper collars are required to expand the Upland G2 EXP model).