The Faithfull Precision Screwdriver Set contains a selection of 30 interchangeable screwdriver bits manufactured from S2 steel. includes a revolving instrument screwdriver handle for precise and accurate control, with a sure grip collar to aid one-handed use push fit hex chuck for rapid bit changing Handle size: 110mm, 160mm with extension fitted. Includes 30 interchangable heads: Hex, Tri, Slotted, Star, Torx, Manufacturer: Faithfull