... 000pcs (1) Housing Materials: steel, aluminum alloy, zinc alloy. wheel material: PP, steel(2) surface: anodizing, zinc ... long life proformance(5) any form of roller can be supplied by us. offer OEM service ... roller(door roller, pulley for door and window,window roller,aluminum housing window roller,nonstandard window roller) sliding window roller(window roller,aluminum housing window roller,door roller ...