SM-RT30 6.3 inches (160 mm) Center Lock Wide Type Resin Pad Only Brand: Shimano / Shimano Model No: SMRT30 Shimano Part No: ESMRT30S2 JAN Code: 4524667634706 *Locking ring fastening tool TL-LR11 TL-FC36 is required.

From the Manufacturer

Shimano Part No.: ESMRT30S2 Type: Center Lock Outer Diameter: 6.3 inches (160 mm) Compatible Pad: Resin Included: Locking Ring Inner Seration Type