Precision Grip Design: Knurled end fittings ensure slip-free connection to both tools and bits, even in greasy or hard-to-reach working conditions. Anti-Whip Safety Design: Engineered with reinforced steel coils to prevent dangerous whipping or tangling during high-speed rotation (up to 800 RPM). Dual-Length Professional Set: Includes both 200mm (8") for precision electronics work and 300mm (12") for deep reaches in car engines/furniture - solving multiple space constraints. Universal 1/4" Hex Compatibility: Securely holds standard hex shank bits and works with all electric drills, manual screwdrivers, and impact drivers (50Nm max torque rating). Exceptional 300° Flexibility: High-grade steel coil construction bends effortlessly while maintaining full torque transmission, reaching screws in winding/narrow spaces that rigid extensions can't access., Manufacturer: Bojueshaw