Features: With polished smooth surface, it works well with high efficiency causing low noise. High temperature resistance, able to operate at a temperature range of -20-200 or so. Adopting premium carbon steel material, solid enough for a long term use. Wide applications in many fields: industrial machines, cars, ships, household appliances, health care system, etc. With 10 pcs in package, you can keep them for spare or just substitutes for those old ones, all is okay. Very practical in our daily life. Specification: Material: Carbon Steel Type: 626ZZ Color: Silver(Shown as pictures) Inner Dia: Approx. 6mm/0.23inch Outer Dia: Approx. 19mm/0.74inch Thickness: Approx. 6mm/0.23inch Application Temperature: -20-200 Quantity: 10 Pcs Weight: Approx. 72g Packing List: 1 x 10 Pcs Ball Bearings 1With polished smooth surface, it works well with high efficiency causing low noise. 2High temperature resistance, able to operate at a temperature range of -20-200 or so. 3Adopting premium carbon steel material, solid enough for a long term use. 4Wide applications in many fields: industrial machines, cars, ships, household appliances, health care system, etc. 5With 10 pcs in package, you can keep them for spare or just substitutes for those old ones, all is okay. Very practical in our daily life.