YS500 Dog Size: Medium to Large Dogs (Over 20 lbs) Features: -No bark dog collar.-Designed for small to medium sensitive dogs.-Rechargeable 2-hour rapid charge lithium polymer battery.-6 intensity levels (2-7) for a wide variety of dispositions. Options: -Available in small/medium or medium/large dog sizes. Color/Finish: -Tri-color LED battery life indicator. Dimensions: -Fits dogs as small as 10 …