Fits on a dogs collars with elastic. (Small fits smaller up to 5/8 width collars Medium for up to 1 inch width Large fits 1 inch width collars no more than 1.5”NOTE:  Some attach to the collar via elastic others are Velcro they are all noted which type they are  Small fits smaller up to 5/8 width collars. They are approx. 3 1/4' X 2'Medium for up to 1 inch width They are approx 4 3/4' X 2 3/4"Large fits 1 inch width collars no more than 1.5”. They are approxc. 5 1/2"X 3'