material: NBR
use temperature:-20° to +80°, the circumferential velocity  below 7m/se.
standard: HG4-338-66 

size: 10*22*8, 
         10*22*12, 
         12*25*12, 
         14*35*10, 
        14*35*12,
         16*30*10
         16*30*12
          20*40*10
          20*40*12
          20*45*10
          20*45*12
          25*42*10
           25*42*12
           28*45*10
the biggest will be 1450*1500*25