Tandem patio door roller,Meet AAMA standard,SS304+SS420 bearing,use in seaside house over 400 lbs door,2 inch diameter wheel,two wheels 10 years gurantee,existing mold,for UPVC sliding door&window,high-quality,10000 cycle testing,20years experience OEM ,manufacture factory,45days delivery,also can produce as your print or sample,30days to make mold and samples.