We purchased both 300 mm and 500 mm 2 pcs but the wonderful place of this ruler is exactly the accuracy of right angle. It is accuracy enough to use other rulers fairly. (As a result of measuring with other precision instruments) Thickness person is also sturdy with about twice the other company's degree. In this price range this precision and ruggedness was felt like Tajima sediment.
Although I used it repeatedly made by another company for several decades, the product here purchased for the first time is very good to see the scale and easy to see. There is also a scale on the inside of 250 mm and it is the highest.
It is us Metal Processing Industry, mainly for seniority but it is very easy to use because the memory is clear and large, and the thickness is relatively thick, so it may be weak at the scene where the bending is necessary