Seam Allowance Additions (Add-Ons) for Acrylic Quilt Rulers of Any Brand

Make Blocks Any Size - No Math! Attach These to the Edge of Your Ruler, and they Do the Math For You   Attaches securely to your 12" ruler with 3 suction cups. Get two sets to use on a 24" ruler. Simply line up to the finished size you want and the precise seam allowance for Squares, Half or Quarter Square Triangles is automatically added when you cut. Built-in Finger Guards Made of virtually unbreakable polycarbonate. Replacement suction cups are available.