PetSafe Deluxe Ultralight Dog Fence Collar, PUL-275. Five levels of programmable correction with warning tone only mode. It also features progressive correction that automatically increases the correction level when your dog attempts to run through invisible fence until your pet turns back. The collar is waterproof with features that protects against false activation. It also has low battery indicator light to let you know when the batteries need to be replaced. This collar is one of the smallest and lightest (2.5 ounces) dog fence collars available on the market and recommended for all pets five pounds and up. Compatible with PetSafe in-ground fences except UltraSmart Rechargeable In-Ground Fence (PIG00-13619) and YardMax Rechargeable In-Ground Fence (PIG00-11115). NOT compatible with PetSafe Wireless Systems!