Fixed bracket with plastic core wheel. Housing made of pressed steel, zinc plating, double ball race,fixed head.Wheel material: Rubber tyre with plastic core, plastic roller bearing.Diameter X tread width: 160x40mmAvailable in 80X29mm, 100x29mm,125X34mm.200X50mm.Load capacity: 50kgs to 180kgsComplies with international quality standard ISO 9001-2000