Dual flange. For stock style open center brake rotors with 6.7" Bolt Circle Diameter and Cross cut bolt mount holes (mount style C). CNC machined aluminum hub that features specially designed brake rotor mounts that are integrated into the hub itself for a unique look.Used with open center (cast front wheel) Touring type front brake rotors & hardware. Premium grade hardware included with each Spider hub allowing it to be installed in minutes onto Ness wheels with simple tools.All Ness wheels are precision machined from radial forged 6061-T6 aluminum and structurally tested. The special hidden hub design includes wheel bearings. Both are installed and pre-set by Ness for optimal radial and lateral runout accuracy. Wheels are compatible with both ABS and non-ABS models. Each hub includes several ABS outer rings. How to order a Ness wheel: Rims and hubs are sold separately. All hubs fit all rims. So pick the hub that will fit your bike; then choose the wheel style; width and diameter you desire.