The PCF-275-19 micro receiver collar has a warning tone followed by mulitple progressive correction levels for the smalles, oldest or most sensitive of cat's. The collar comes with a low battery light indicator and is waterproof in case your pet gets caught in the rain. With the purchase of the additional receivers, you can add as many pets to your containment system as you'd like. This receiver-collar is the smallest, lightest and most advanced cat collars on the market today and now features a 3 year warranty.