Material:PP for back up pad,and the middle layer is EVA. Use:for ... 4",4.5",5",6",7" This DIY pad is common quality pad,it is made with PP for back up ... pad,and the middle layer is EVA.this is ... market in the world use this grade of pad.because it is cheap.Material:PP for back up ... pad,and the middle layer is EVA.Use:for DIY marketSize:3",4",4.5",5",6",7" DIY polishing pad