Failed to load media. The carpenter's ruler is ready to use. The knob screw is a good size and easy to tighten/loosen without being bulky and getting in the way. The wooden block is strong and smooth so it's easy to hold in your hand and glides smoothly over the edges of whatever materials you're working with (wood, acrylic, plexiglass, cardboard, etc.). The 1.2mm thick metal gives the ruler strong rigidity and prevents it from bending easily. Measurements and angles are very accurate, compare caliper, combination square, speed square (frame) measurements to frame square to ensure the edge is straight and all measurements match perfectly.