For dogs 20 lbs or greater. LCD screen displays exact level of stimulation even in dark or low light conditions. Regular/mild setting toggle switch, gives you the option to adjust the range of stimulation levels for your dog's sensitivity. Three bar battery life indicator. System includes: one transmitter, two receiver collars, a lithium Polymer battery charger and splitter cable, a test light, an owner's manual and a carrying case. Precise stimulation level (0-127) 1 mile range Nick', 'Constant' and non-stimulating pager/vibration 2-hour rapid charge Lithium Polymer batteries Fully waterproof collar/receiver and transmitter