Features 7 intensity levels for a wide variety of dispositions. Level "P" only emits a vibration, whereas levels 2-7 emit a vibration followed by stimulation. With proper repeated usage, when level "P" is used, your dog can learn to stop barking with the vibration warning so that stimulation will no longer be necessary. The fully waterproof receiver features two-hour quick charge Lithium-Polymer batteries, antimicrobial plastic casing, LED battery life indicator, and surgical stainless steel contact points to minimize irritation to the dog's skin. Testing level (T) that allows for testing of the collar without any electrical correction. Fits dogs as small as 10 lbs. (receiver weight: 4.0 ounces) Fits neck size up to approx 27".