This flexible shaft can be used for general screw cordless drill, it can also be used for electric screwdriver. Flexible shaft head can be mounted hexagonal shank (1/4 shank) screwdriver bits, mainly used in computer case, electrical cabinets, furniture, electrical appliances and other narrow spaces where screwdrivers can not work normally.Features:Metal material, durable and portable, Flexible out shield protects your hand while inside shaft rotates.Fit hex screwdriver or screw cordless drill shank diameter: 6.35mm (1/4").Shaft is very flexible and can bend up to 300 degrees. Bit holder keeps fasteners and bits secure while driving.Bends, twist and turns to use drill into tight and confined spaces. Specifications: Material: MetalHex Shank: 6.35mm (1/4")Inner Hexagonal Head: 6.35mm (1/4") Total Length: 300mm / 11.81" , 400mm / 15.74"(Optional)Quantity: 1Weight: Approx. 99g(300mm), 129g(400mm)Package Includes:1 x Flexible Shaft Extension Bit Holder Note:1. Please allow 1-3mm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos maybe showing slightly different from the real object. Please take the real one as standard..