This 9 piece low profile impact Spline (XZN triple square) socket bit set is ideal for use in any application where access is restricted. The set includes M4 to M18 bits in 1/4", 3/8" and 1/2" drive sizes. Heavy-duty bits manufactured from chrome molybdenum with a one-piece construction for strength and durability and a black phosphate finish for improved corrosion resistance. High contrast, easy to read size markings make it easy to find the right socket at a glance and the set is presented in a fitted EVA foam tray for organised tool drawer storage.