PetSafe Deluxe In-Ground Cat Fence Receiver Collar For the PetSafe Inground Cat Fence and Other PetSafe Wired Fences (Excluding the YardMax) This Collar Has the Smallest Collar Receiver of All Underground Electric Pet Fences Collar Strap has Small Elastic Break Away Section to Prevent Kitty From Choking Himself when Sticking His Head Into Tight Spaces Best for Cats that Are 6 Pounds and Over 4 Adjustable Levels of Static Correction and a Tone Only Mode that Alerts Your Pet with a Beep