The Ko-ken RS4129/5-L75 1/2" Square Drive Bolt Twister Set is a practical solution for recovering broken bolts with missing heads, designed for efficient fastener removal. This set includes five bolt twisters in sizes 8mm, 10mm, 12mm, 14mm, and 16mm, each crafted to securely grip the broken bolt. To use, simply drill a hole in the center of the broken bolt, insert the bolt twister, turn left until it engages, and continue turning to extract the bolt. With a length of 75mm, each bolt twister is conveniently organized on a 150mm rail for easy access and storage, making it an indispensable addition to any toolbox.