Suitable only for lever-start screwdrivers - Very easy to attach - The angle drives feature a built-in 1/4" hex bit holder - For the more powerful screwdriver models, a 3/8" HEX drive is available - the gearboxes are maintenance-free, durable, and help securely tighten even hard-to-reach screws - for screwdriver models: BC830L, BC850L, 8230L, 8240L, 8250L