The MRC R4ZZ is an inch-series, single-row radial deep groove ball bearing manufactured by MRC (a brand under SKF). It is a small Conrad-type bearing designed for high-speed industrial automation and motion control applications that handle radial and moderate thrust loads. Key Specifications Bore Diameter (Inner): 0.2500 inches (1/4 in) Outside Diameter: 0.6250 inches (5/8 in) Width: 0.196 inches (approx. 5 mm) Enclosure Type: Double shielded/sealed ("ZZ" indicates two protective closures to keep grease in and dirt out) Load Capacities: Supports a 332 lbf dynamic load and a 139 lbf static load Precision Rating: ABEC-1 standard industrial precision