GROOVYPETS 650 Yards Remote Dog Training Collar Obedience Trainer:Rechargeable Waterproof Collar w/10 Levels of Adjustable Static Stimulation,Intuitive Control of Tone and Vibration (3-Dog Trainer) A solid 600 meters/650 Yards remote control range; Genuinely 100% waterproof dog collar receiver; Small(6cmx3.5cmx3cm) and light weight(2Oz/58g) Rechargeable receiver; Collar strap adjustable from approx 20cm to 60cm (from approx 8 to 23). You can also use your own collar strap as long as it does not exceed 2mm in thickness. Intuitive control of tone and vibration(push and hold the Beep button will change tones; push and hold Vibration button will boost vibration levels ); 10 level of static stimulation (from zero to 9, you can make the collar "shock-free" when zero level is selected); All channel control lets you correct two dogs or three dogs at the same by pushing a single button