EXPANDABILITY: The 2300NCP EXPANDABLE performance receiver design offers advanced technology to train up to 2 dogs. With a high output and the ability to expand, you’ll be able to train multiple dogs at once during obedience training..75-MILE RANGE: The range of the 2300NCP EXPANDABLE receiver is perfect for any and all simple commands for your dog. With a range of.75 -mile, this e-collar is perfect for advanced level pet training, competition training, police K-9 work, or any type of hunting.FULLY WATERPROOF SYSTEM: The 2300NCP EXPANDABLE receiver is fully waterproof. If your hunting or fieldwork leads you and your dog into wet/damp areas, you won’t have to worry about the collar malfunctioning.CORRECTIONS: This receiver has two different correction types. The first correction type is a Nick (quick .5-second) and the second correction type is a Constant (up to 12 seconds). The e-collar also has a HPP (High Performance Pager) which offers a clear vibration to alert dogs while training. Find the right fit for you and your dog with this dynamic e-collar.DOG SIZING: The 2300NCP EXPANDABLE receiver is perfect for medium to large dogs with its durable design. It’s designed for dogs 35 pounds or more and is perfect for mild to stubborn dogs.Replacement or additional receiver for the.75 Dogtra 2300NCP EXPANDABLE, with an orange strap.