[Scope of application]Universal 1 or 4 inch (about 0.6 cm) quick hex shank and 1 or 4 inch (about 0.6 cm) hex socket, convenient for placing different commonly used 1 or 4 inch (about 0.6 cm) drill bits. Fits most electric drivers, hand drivers and drills such as t25 and t20 drills etc. []The drill socket adapter is made of Metal, which is , and strong, which guarantees its service life. [How it Works]This bit holder keychain has a ball bearing to hold the bits, and they work like a slide or snap lock. This allows you to easily change the drill bit with one hand. [Large Capacity]The lock of the drill holder can carry drill tools weighing up to 500 grams. The drill bit is not easy to drop. 1 or 4inch Hex Shank Screwdriver Bit Holder: Set includes 1 or 4 Hex Shank Keychain Extension Rods with Black Metal Hanging Buckles Compatible with most 1 or 4 Speed Hex Handles and 1 or 4 Hex Sockets and Assortment of electric screwdrivers, hand screwdrivers and drill bits. Portable and Wide Application: Small size, easy to carry, can be used for drills, screwdrivers, etc. Can also be used as a keychain. type: A Colour:black Material:Metal Package Contents: 12 x 1 or 4 hex shank handle keychain extension rod 2 x metal hanging buckle Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.