Astro 78803 1/2-Inch Drive Thin Wall Flip Impact Socket Set with Protective Sleeves 3 PC Each impact socket comes with protective sleeve. Made of industrial grad chrome molybdenum (chrome-moly) steel alloy. Sizes: 17mm x 19mm, 3/4" x 13/16", 7/8" x 21mm Includes 3" extension bar Weight 3 lbs.