ACDelco 20631S Professional Molded Coolant Hose Has a heat and ozone resistant cover to increase the life of the hose Comes with a protective sleeve to help duplicate GM OE designs for proper fit and function Made of re-engineered materials to resist vacuum collapse and also reduce the need for internal springs in many applications Installs without buckling, bending out of shape, or straining at the connection for easy installation Inside diameters ranges from 1?4 in to 1 in to fit different types of vehicles