Knitter’s Pride Rainbow Knit Blockers were designed by knitters for knitters to make knitting lives easier. The ease of handling the blockers substantially speeds up blocking on all types of projects. The design helps maintain even tension across the width of the blocking pins. Ideal for blocking straight edges like sweaters, shawls and scarves. Anchor holes in each blocker allows the user to attach string along large sections which can be pulled and pinned to maintain consistent tension. These knit blockers are made using tough plastic with embedded sharp, sturdy and rust resistant stainless steel pins. There are two different sizes to manage different shapes when blocking: there are 12 blockers with 8 pins and 8 blockers with 4 pins.