R4AZZ Shielded Ball Bearing 1/4" x 3/4" x 9/32" R4AZZ Shielded Ball Bearing, this is a popular size that could be used in many applications, the inner diameter is 1/4" inch, outer diameter is 3/4" inch and the width is 9/32" inch, each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease and bearing is made of Chrome Steel.