Model: R4 ZZ Quantity per Package: 2 Pcs Material: 100% Chrome Steel Protection: Metal Shield on both sides Greased / Lubricated: Yes Bore (Inner) Diameter: 1/4" Outer Diameter: 5/8" Width (Thickness): 0.196" Supported Revolutions per Minute (RPM): 38,000 Dynamic Load Rating: 1489 N Static Load Rating: 618 N PGN's R4z (1/4"x5/8"x0.196") is a single-row bearing that supports radial loads, made with Chromium Steel providing superior quality and durability. It comes pre-lubricated and shielded to keep the lubricant in and contaminants, dirt and debris out.