STEELMAN 95379 3-Piece Serpentine Belt Wrench Set Sizes: 13 millimeter or 1/2 Inch hex, 14 millimeter hex, 15 millimeter hex, 16 millimeter or 5/8 Inch hex, 17 millimeter hex, 18 millimeter hex, 19 millimeter or 3/4 Inch hex, 3/8 Inch square, 1/2 Inch square, 3/4 Inch square Slim head design allows access to tight areas found in the tensioner area on some front wheel drive vehicles Heat treated and nickel chrome plated for durability, appearance and long tool life