"Chew Clean" grooves perform a gentle "squeegee" action on teeth and gums. Reduces plaque and tarter build-up. Made with Ultra-Flex puncture resistant, natural rubber that is non-toxic, non-abrasive, non-splintering, and does not get sharp when chewed. Dental Kong also comes with a removable rope.Sizes: Small-(18"L including rope)Medium-(22-1/2"L including rope) Large-(5"L does not include rope)X-Large-(6" L does not include rope)