Đồng hồ đo độ cứng cao su, nhựa PTC Shore C Scale Ergo Durometer 409C
Model 409C is a durometer that has a smaller base then the 307CL to make it easier to test the hardness of smaller surfaces. ASTM Type C Scale Durometers Measure the Hardness of Medium Hard Rubber, Elastomers, and Thermoplastics.