The SportDog Extra Receiver for SportHunter is durable and rugged enough for close-working hunting dogs. Flexible enough to offer a wide choice of stimulation levels that will allow you to work with even the most sensitive dog. Continuous and momentary stimulation plus "hot" button and tone-only. One-hand operation with "tactile", thumb-activated slide-wheel makes changing levels easy, even with gloved hands. Stop-notches make returning to previous level easier.