Adding subtle refinements to the proven 1900-design, the Dogtra 1900S/1902S E-Collar Dog Training System delivers easy-to-use dog training performance. This high performance trainer helps you direct up up to 2 dogs within a 3/4 mile range, putting up to 127 levels of nick or constant stimulation with low/high settings at your fingertips. Waterproof transmitter features an easy-to-use rheostat dial that lets you gradually increase the stimulation to the exact level you need. Transmitter also offers a checkered grip for a positive feel, a LCD screen that displays the exact level of stimulation in use and battery life. The 1900's E-collar features a slim design receiver/collar that also features a non-stimulating pager/vibration feature. Waterproof transmitter Low- to high-power system features rapid charge (2 hour) rechargeable lithium polymer batteries in the transmitter and collar. Comes with gear bag. 1900S comes with 1 collar. 1902S comes with 2 collars. IPX9K waterproof rating. Easy-to-use training system for up to 2 dogs with medium to soft temperments Up to 3/4 mile range 127 levels of nick or constant stimulation Waterproof transmitter with checkered grip -easy-to-use rheostat dial stimulation control LCD screen - displays the exact level of stimulation in use Battery life icon Low- to medium-power system designed for dogs as small as 35 lbs. Slim design receiver/collar with non-stimulating pager/vibration feature Rapid charge rechargeable lithium polymer batteries in transmitter and collar