Size: 1/4"-2",22-50mm 1. material: CRV ,s2 and 50BV30 2. various surface finishing 3. heat treatment, forged.. High quality chrome vanadium steel, cold forging*Chrome plated treatment,high hardness,high flexibility Specifcation of spark plug socketProduct To Encode Product Size Pcs/CtnD05001 6×65 500D05002 8×65 500D05003 10×65 500D05004 12×65 500 Professional Magnetic socket (CRV)