Kong rubber Biscuit Ball has a hollow center and bone-shaped ports (side holes). The 1/2" thick wall is made of the same tough (red) rubber as other Kong products. Great for indoor and outdoor snacking fun.
Small - Dogs under 30 lbs.
Large - Dogs over 30 lbs.
The biscuit ball is the best kong I've tried. Others either don't have enough holes for treats or have flaps that can be chewed and swallowed. This is a fun toy and a safe one as well. Buddy now has one for home and one for grandma's house.