DT Systems 1 Dog H2O 1850 Dog Stimulation Collar Up to one mile range; lightweight, waterproof collar and transmitter; maxx-range internal antenna system in collar belt; no-slip/soft-grip transmitter floats on water! 18 adjustable intensity levels of momentary (nick') stimulation and continuous stimulation; gentle touch system extra mild stimulation Three beeper functions - locate, run & point mode, point only mode Expandable to 2 dog system with h2o addon collar units (sold separately) Rechargeable nimh battery system; built in safety shut-off system for improved battery life and reduced cost of operation Expandable to 2 dogs with Add-On Collars Lightweight waterproof collar and transmitter 16 levels of intensity, adjustable from the transmitter Beeper with locate, run and point, and point only modes