Ball Bearings 25x37x7 Chrome Steel With Snap Ring 6805ZZNR Ball Bearing with Snap Ring (C clip), this is a popular size that could be used in many applications that uses this size 25mm x 37mm x 7mm. Bearings are made of Chrome Steel and can rotate up to 18,000 rpm, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease