Đồng hồ đo độ cứng cao su, nhựa PTC Shore OO Scale Pencil Durometer 203
Type OO durometers measure the hardness of polyethylene foam roll, sponge rubber, very soft rubber.
This durometer's 1/2" diameter base (1.3cm) is the smallest base permitted by ASTM D2240 specifications. This allows it to be used in confined or hard to reach areas other durometers cannot test.