If You Have Ever Misplaced Your Drill Chuck, You Will Know The Importance Of Having A Tool Like This Available In Your Tool Box. This Drill Chuck Has 4 Different Popular Sizes, One Of Which Is Sure To Fit Your Drill. (handy Hint: You Should Tape Your Drill Chuck To The Power Cord So It Doesn't Get Lost). But If It Does, You'll Be All Set!* Solid Metal * Sizes 1/4, 3/8,1/2, & 5/8" * Or 6, 10, 13, & 16mm * Suitable For Most Drills