TWO DOG SYSTEM Nick and Constant Stimulation options; Waterproof collar & Transmitter; 1 mile range; World's only floating transmitter; USER EXPANDABLE TO THREE DOGS! If you’re looking for a training collar that’s great around the house as well as in the field, look no further than DT Systems’ H2O 1810 PLUS. This 1 mile range collar system has 16 levels of momentary (or Nick) and Continuous Stimulations. Both the collar unit and the transmitter are completely waterproof. In fact, the transmitter will actually float on water; perfect for waterfowlers who spend more time on the water than the ducks do. And if you ever decide to get more dogs, the H2O 1810 PLUS can expand up to a three-dog system with Add-On Collars (sold separately). Features Digital technology Expandable to 3 dogs with Add-On Collars (sold separately) Up to 1800 yard (1 mile) range Lightweight waterproof collar and transmitter No-Slip/Soft-Grip transmitter floats on wa...