SportDOG WetlandHunter 400 Yard Remote Trainer, SD-400CAMO 400 yard range Compact, high-output receiver 2.8 oz, with a compact 3.2 oz transmitter Expands to 2 or 3 dogs, (need to purchase additional receiver / collars) Up to 16 levels of continuous and 8 levels of momentary stimulation. Replaceable, rechargeabel NiMH batteries