Socket Set 1/2″ Drive TX Bit 23 Pieces TT Tray Chrome vanadium satin finish bit holders included Grub screws to retain the bit in place, especially useful when working in difficult to reach places Designed and manufactured to DIN 3126 & ISO 1173 Organised in a tool tray module size 1 (TT1) Set consists of 20 bits, regular and long for internal TX heads. In addition includes 2 adaptors and a 2mm hex mini screwdriver.