Take the edge off your high-strung pets with Dogtra's Edge RT Expandable. Color-coded receivers (black, blue and green) are compatible with up to three dogs and boast a one-mile range. Low, medium and high buttons on the tubular handheld transmitter make no-look operation super easy. Eight-level selector-style intensity control also has a pager feature. Waterproof transmitter and collar. Powered by two rechargeable lithium-polymer batteries (included). IPX9K waterproof rating. Manufacturer's two-year warranty. Compatible with up to three dogs One-mile range Low, medium, and high buttons Eight-level selector-style intensity control Waterproof transmitter and collar 2 rechargeable lithium-polymer batteries included