There are some who struggle with the concept of using a form of electronic correction on their dog. This system is for them. Collartron is now carrying the 'Pager Only' communicator which has all the features of the standard electronic training system. This system looks very similar to the ET-300 , has a slimmer collar and will fit most dogs . Provides 100 levels of adjustable vibration only with no electronic correction. Perfect for deaf dogs too. Fully waterproof and shockproof, and of course expandable to two collars.