SPORTDOG FieldSentinel 825 1/2 Mile Remote Trainer (FS-825)

Designed for control at a distance of 1/2 mile range; BodyGuard Technology monitors heart rate and the intensity/duration of exertion to determine your dog's exhaustion level; Lithium-ion batteries feature 2-hour quick charge and low battery indicators; Tone, vibration, and 7 static stimulation levels allow you to customize training; Both the remote and collar are waterproof and submersible to 3 feet; Expandable to 2 dogs with an additional collar. Switch between dogs with the toggle switch on the remote; Compatible for dogs 8 pounds or larger with neck sizes 5-22 inches; Collar without strap: 3.7"L x 1.96"W x 1.53"D; Remote with antenna: 5.15"L x 2.1"W x 1.22"D