... 17 1 20 60 100 24 0.043 1/2" 12.5 21 2 20 60 100 43 0.085 5/8 ... " 16 25 2 20 60 100 48 0.170 3/4' 19 28 2 20 60 100 58 0.115 ... 1" 25 35 2 20 60 50 42 0.11 ... .Material:SBR Natural rubber; 2.Size: 1/4", 5/16", 3/8",1/2",5/8",3/4",1"3 ... Structure: Inside bond layer + reinforcing layer ( second reinforcing layer for1/2",5/8",3/4",1")+ 8.outside bond layer; outside ...