... 50mm; 2. Color: Black, white, Red, Yellow etc. Screw ball rubber caster wheel:Product Feature:1. Dia: 50mm;2. Color: Black, white, ... are available;4. Competitive Price;5. Superior Quality, TUV CERT ISO9001:2000 quality assurance6. OEM and ODM orders are welcome7. ... America, Japan and Europe owing to our competitive prices, quality oriented products (all the production accord with ISO9002 Standard), ...