With older drill models, you're going to need a chuck key to replace bits. With Ryobi's A10MK21, you'll be able to work with most 1/2" keyed chucks to get what you need done. Its metal construction is sturdy and long lasting, and it has a center hole to thread through a carabiner or lanyard. Bring this with you to the jobsite or tape it to your tools so you never forget it! With three different sizes for chuck pilots, you're likely to have the right key for your 1/2" chucks with you. Do it right with Ryobi.