KoolKani 650 Yards Remote Dog Training Collar Obedience Trainer:Rechargeable Waterproof Shock Collar for Small, Medium, Large Dogs This 2-dog remote trainer can get each dog's instant attention with a vibration alert by pushing a single button; Collar strap adjustable from approx 20cm to 61 cm (from approx 8" to 24") OR use your own collar strap as long as it does not exceed 2mm in thickness. Rechargeable dog collar receiver with lasting battery life, one single full charge lasts up to 7 days, great for multiple training sessions without worrying about the battery; Three correction modes: beeping warning tone (10 groups of different frequencies) & vibration (10 levels) & static stimulation (10 levels); The static stimulation is not electric shock, safe and humane for all dog size; You can use any one or any combination of the correctional signals with or without verbal command; Genuinely 100% waterproof and weatherproof dog collar receiver. Great for indoor or outdoor behavioral and obedience training, field trip, hunting. Your dog can wear it without worrying about water or rain;