SportDOG SportTrainer 875 - The SportDOG Brand SportTrainer 875 is designed for field training and hunting with close-working dogs. Featuring an easy-to-read OLED screen, you can view the selected dog, static stimulation level, and mode, as well as battery status, with just a glance. This, combined with large plus/minus buttons to easily toggle among dogs and stim levels, makes the SD-875 especially suited for multi-dog hunting situations. Expandable to 3 dogs For dogs 8 pounds or larger with neck sizes 5in - 22in Charge in 2 hours, last 50-70 hours per charge