3-piece set of different lengths (60 mm, 100 mm, 150 mm) The quick-change and release system allows for quick installation, locking and unlocking of bits. The magnetic bit holder allows for comfortable recording and fixing of screws. Hex Shank: 1/4" / 6.35 mm hex shank easily fits into cordless screwdriver, drill and hand screwdriver. For extending all types of screwdriver bits Product: Magnetic Screwdriver Bit Holder. Contents: 3 pieces. Length: 60 mm, 100 mm, 150 mm. Color: Black and silver. Shank: 1/4" (6.35 mm) hex shank. Drill Bit Holder: The quick-release holder has a locking mechanism, built-in magnet and automatic pop-up head. : Stainless steel. Features: Suitable for drill, screwdriver, batch head, manual screwdriver and other tools. Extend all kinds of screwdriver bits. With these accessories, you have screwdriver conversion capabilities. Sturdy, durable and quick change with high efficiency. Strong magnetism: Limit the position of the screwdriver and is adjustable.