Shaft Diameter: 5/8 inch (0.625") Mating Ring Outer Diameter: 1.25 inches (or 1-3/8" depending on seat configuration Standard Materials: Buna-N elastomers, carbon graphite primary ring, ceramic stationary seat, and stainless- steel hardware. Operating Limits: Handles pressures up to 75 PSI and operational speeds up to 1750 RPM. Temperature Range: Tolerates extreme temperatures from -40°F to +400°F.