1. Built-in precise micro bearing; 2. Zinc alloy main support with chrome plated; 3. Elegant design and rust resistance. Detailed product information:Materials: Micro bearing, 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 AlloyChrome ...