... , PA66, Zinc alloy;Roller dimension: 21mm---25mm;Profile type: Round type, V type, U groove type,etc.Item NoMain Support MaterialsSurface treatmentUsageRS10087Zinc AlloyChrome platingUpper rollerRS10088Zinc ... of stainless steel. 2. Rollers can be 22-26mm, with V type, round type, U groove type, etc. RS series nylon shower door roller