1.Quality of the door roller reliable 2.Reasonable price of the door roller 3.The door roller export to worldwide 4.long-life DRAWING: Produce NameModelMaterial Size(length/width/hight)Door Roller XF-B23 Aluminium/nylon 35*34*34mm This door roller is made of nylon with bearing,fixed by Axis ,has the specialty of wear-resisting,long life,is your first choice of purchashing.