Description 4 Piece 1/2 in. Drive Thin Wall Flip Impact Socket Set with Protective Sleeves Features and Benefits: Sizes: 17mm x 19mm; 3/4 in. x 13/16 in.; 7/8 in. x 21mmIncludes 3 in. extension barMade of industrial grade chrome molybdenum (chrome-moly) steel alloyEach impact socket comes with protective sleeve