Shinwa medium Japanese carpenters square with deeply etched metric full mm graduations inside and outside on both faces.
Hard chrome plated stainless steel, so no worries about rusty fingermarks, and hardened to Hv320+ for the perfect balance of stability and springiness.
Japanese carpenters squares are flat, they are used in the same way as a framing square, with one leg hung over an edge with its face acting as a stock.
300mm long leg, 15cm short leg
Square to better than 0.1mm/100mm
Conforms to JIS B7534
Made in Japan.