EBaySmall in size but big when it comes to functionality. Supplied as a pair and probably one of the most useful tools of this type. The squares are approximately 90mm on each side (18mm thick) with graduations in both metric and imperial, 0 to 80mm and 0 to 3.1/2". Each is provided with a removable steel base, which you can use to register the square against an edge when marking or checking a mitre or square. The steel base is held in place by rare earth magnets set into the sides of the square. The magnets hold the square in place on cast-iron machine tables for setting or checking blades and fences at 90° or 45°. The scale along the edge allows you to use the square as a height gauge for saw blades and router cutters. Yet another function is as assembly squares using a couple of clamps. These squares are perfect for ensuring the joint is at exactly 90° when used on an internal corner. The notches on each side allow the use of Fence Clamps for a neater clamping arrangement. In the centre of each square is a 20mm hole. The hole allows the squares, in conjunction with a 20mm dog, to be used on a multifunction bench as reference or to clamp against.