Katrinkles Granny Square & Guage Swatch Blocking Board. A handy tool for blocking any motif or swatch. The pins hold your piece firmly in place and the gird provides plenty of size variations within about five inches. The board and 12 pins are wooden and come with a small cotton bag to store the pins when not in use. Full board size is 5.25" x 5.25" with 144 holes. Pins measure 3.5" long.