Ryobi AR2019G 3 Piece 1/4" Bit Holder Set (Includes Magnetic Bit Holder and 2 x Screw Guides w/ Sliding Collars) 2 3/8" MAGNETIC BIT HOLDER will keep your bits in place, using magnetic force to prevent them from wobbling while in the chuck 4 3/4" and 3 SCREW GUIDES feature adjustable sleeves that keep your fasteners straight, preventing damage to your wood and other surfaces EXTEND YOUR REACH: These bit holders also act as extensions, allowing you to drive fasteners into hard-to-reach places that go beyond the capabilities of your drill by itself SPEED LOAD COMPATIBLE: The hex shanks of these bits will work with the Ryobi Speed Load bit changing system STACKABLE: You can fit these extensions into each other to provide even more reach than you thought possible