"Designed for the most demanding environments, Dogtra Edge RT E-Collar Dog-Training System offers the simplest solution to the most complex training. The ""no-look"" one-hand operation allows you to always keep your eyes focused on your dog. The 8 levels of nick and constant stimulation coupled with combination buttons and non-stimulating pager vibration, offer a wide range of adjustability for every dog and every training situation. Dogtra EDGE RT E-collar comes with a durable, waterproof receiver collar and tube-shaped transmitter with 1-mile range and up to 3-dog expandability. The tube-shaped transmitter with selector step dial for stimulation control fits ergonomically in your hand. The receiver collar has 5/8"" surgical stainless steel contact points, which can be replaced with longer 3/4"" contact points for dogs with thick or long coats. IPX9K waterproof rating ensures reliability in wet conditions. 2-hour rapid-charge batteries have you training in a flash. Dogtra Edge RT E-Collar Dog-Training System expands up to 3 dogs as small as 35 lbs. System includes transmitter, receiver, battery charger, belt clip, test light, lanyard, contact point extensions, adjustment tool, splitter cable, and carrying case. ""No-look"" one-hand operation 8 levels of nick and constant stimulation Combination buttons Non-stimulating pager vibration Durable, waterproof receiver collar Ergonomic transmitter with 1-mile range Up to 3-dog expandability 2-hour rapid-charge batteries Works with dogs as small as 35 lbs."