Knitter's Pride Rainbow Knit Blockers are a great way to block knitting projects! They're so easy to use, they'll speed up the blocking process, and the vibrant colors can assist with visual blocking unusual shapes. The novel design helps maintain even tension across the width of the blocking pins - working best on straight edges. Anchor holes in each blocker allow you to attach string along large sections which can be pulled and pinned to maintain consistent tension. Rainbow Knit Blockers are made using strong plastic with sharp, sturdy & rust resistant stainless steel pins in two sizes in order to handle different shapes when blocking. Each set includes 20 Knit Blockers: 12- 8 pin blockers, approximately 3" long 8- 4 pin blockers, approximately 1½" long All pins have a total height of 1¾" with an exposed pin length of ¾"