Mr. Pen- Interlocking Blocking Mats, 12"x12", 4 Pack, Blocking Mats for Knitting & Crochet Projects with 50 T-Pins, Knitting Blocking Mats and Pins, Crochet Blocking Board for Crocheting is a Knitting & Crochet option for everyday use, business supply needs, resale shelves, or household stocking. Review product size, pack count, and shipping details before checkout.