Drop forged, chrome vanadium steel, heat treated, black oxide finish for durability. ? Use for tamper-proof star fasteners in today’s car, trucks, SUVs, appliances, etc. Contents: ? 6pcs 1/4″ drive star bit socket sizes: SD-10, 15, 20, 25, 27, 30 ? 6pcs 3/8″ drive star bit socket sizes: SD-40, 45, 47, 50, 55, 60 ? 1 pc 3/8″ drive (f) x 1/4″ drive (m) adapter ? 2pcs clip on storage rails.