18 levels of Static Correction, automatically adjusts to your dog's temperament starting at the lowest level Three intensity settings accommodate the most sensitive and the most stubborn dogs Patented Perfect Bark technology for the most reliable bark detection Low battery indicator QuickFit?buckle provides a quick release and a perfect fit every time (patent pending) Durable, waterproof Receiver Collar Flexible collar provides a comfortable fit Lifetime Limited Warranty Height: 1.5" Width: 2.5" Depth: 1.25" Weight: 4.0 oz. Uses a PetSafe Battery: RFA-67 Adjustable collar for neck sizes 8"-28" Progressive correction feature increases correction to next strongest level if dog continues to bark Safety time out will shut off the correction for 3 minutes if the dog barks more than 15 times in 30 seconds Uses vibration sensor to sense for barking Not recommended to use for more than 8 hours at a time Dog should be at least 8 lbs. Low Battery Indicator