The great advantage of a folding rule over a tape measure is its rigidity – it won’t bend or twist, even when fully extended, and provides a solid edge that you can mark against.
Made of birch with durable steel tips and joints, this rule has Imperial and metric markings on both sides, graduated in 16ths and millimetres respectively. The markings are fine and crisply printed with large, easy-to-read numbers.
Setting the rule on its edge lets you eliminate parallax error when marking; with just a few sections folded, it will stand on its own, freeing your hands for other duties. Detents firmly hold the joint positions fully open or folded.
It is 2m (almost 80") long overall and folds to only 8 5/16", small enough to carry in a tool belt or apron pocket.
Once a common tool, a good-quality folding rule is becoming harder to find.