... roller,window roller. standard or nonstardard bearing. POM,nylon covered. Long life. Pulley:1,Standard bearing: 608,608z,608zz,625,625z,625zz ... ,693,693z,693zz.2,Bearing steel material: carbon steel ... make the nonstandard bearing as per customer requirement,OEM with sample or drawing.4,Coating plastic material: 1, Nylon. 2, ...