Widely Used: The flexible extension drill (black) is about 300mm and is soft and flexible. It can be twisted, folded in a narrow place or rolled up without any difficulty. The flexible bit holder of 2 different lengths is used for cartridge or electric screwdriver type manual drills and mainly used in computer chassis, electrical cabinets, furniture, electrical appliances and other screwdrivers with narrow space cannot work in the environment . Safety: The flexible shaft of the screwdriver is designed with a flexible handle and easy to bend. The flexible shield protects your hand when the inner shaft rotates. Convenient: This flexible shaft can be used with a regular hand chuck electric screwdriver (1/4 collets). In some special environments, use the flexible drill bit extension to protect your hands and allow you to work comfortably. Material: Flexible Soft Drill Extension (Black): Made of high carbon steel and plastic which is convenient and durable to use. And the flexible drill bit extension (silver) is made of special metal. What you get 1 flexible drill bit holder (300mm, black) + 2 flexible metal extension drill holder ( 300 mm and 200 mm, silver).