Shore A Durometer, test pressure needle dimension is 0.79mm, used to test the hardness of Medium and low hardness material, such as plastic, fur, rubber, polyester, wax and etc..
Shore C Durometer, test pressure needle dimension is 2.5mm, used t test the hardness of low hardness materials such as foamed foam, sponge and etc..
Shore D Durometer, test pressure needle dimension is 0.1mm, sed to test the hardness of high hardness material, such as hard rubber, resin, acrylic, glass, and etc..