The SPR (Super Pro Ranger) 5100 features a 2 mile range made possible by our exclusive Maxx-Range 360 antenna technology to ensure positive FM signal reception, no matter the terrain. Waterproof collar and transmitter. Remote and collar units have rechargeable Li-Poly batteries with our SmartLED light that lets you know when charging is complete and how much charge is left during use. Also features fully adjustable Instant (Low-Med-High) stimulation buttons via simple programming options.