Description: Premium Material: Each socket adapter is made of heat-treated treatment hardened chrome vanadium steel for superior durability, suitable for heavy duty impact drivers. Secure Hold: Includes a bit holder with magnetized ends to securely hold 1/4-inch(6.35mm) bits. The selectable size makes it compatible with the most of brands of electric drill and screwdriver handle tools.The spring ball bearings on each square head are securely locked in the socket to avoid slipping during use. Function: Compatible with common to heavy-duty power tools, drivers, hand wrench, and screwdriver handle tools for flexible uses. Suitable for a screwdriver handle or electric screwdriver tool (hexagonal hole or three-jaw chuck) drive sleeve to use. One Organized Storage: Convenient holder and storage case let all the socket adapters stay organized to take your set on the go. Socket adapters are perfect for car repair, DIY and most general home repairs. Specification: Size: Hex Square Connector : 1/4 '' x 1/4 '' x 2 inch(51mm) 3/8" x 1/4 '' x 2 inch(51mm) 1/2" x 1/4 '' x 2 inch(51mm) 1/4 ''x 1/4 ''x 2.6 inch(66mm) 3/8" x 1/4 '' x 2.6 inch(66mm) 1/2" x 1/4 '' x 2.91 inch(74mm) 1/4 ''x 1/4 '' x 0.98 inch(25mm) 1/4 '' x 1/4 '' x 1.18 (30mm Hex Hex Sleeve: 6.35x61mm/0.25 x 2.4inch Package Includes: Set A: 8 x Hex Shank 1 x 1/4" Hex Sleeve 1 x Storage Base Set B: 8 x Hex Shank Impact Drivers 1 x 1/4" Hex Sleeve 1 x 1/2" to 1/4" Impact Driver Adapter 1 x Storage Base Note: 1. Please allow 1-3mm error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!