This Ernst Manufacturing accessory pack features twist lock socket clips and ratchet and extension holders to add on to any Ernst socket organizer. Twist lock clips keep sockets secure for transport. They easily clip on to socket rails and placement can be adjusted. Ratchet and extension holders Easily clip on to socket rails and hold a wide variety of tool sizes. Keep ratchets, extensions, and sockets all together in one easy place! Includes 15 twist lock socket clips and 2 ratchet and extension holders in 1/4", 3/8", and 1/2" Drive sizes. Made in USA. Lifetime guarantee.