Dogtra 1902S 3/4 Mile Range 2 Dog Training Collar System Precise stimulation levels (0-127) Ergonomic slim receiver for dogs as small as 35 pounds Fully waterproof collar/receiver and transmitter. Rheostat/Volume Dial with Stimulation Levels 0-127 Nick, constant, and non-stimulating vibration modes Water Excelling Enhanced Contact Points. Low to High Power Stimulation