e*spec wheels use a custom hub that increased dynamic load ratings by 53%, and decreased axle deflection by 37%. Mechanicsm is triple-sealed, and uses a steel axle w/pinch bolt to decrease deflection.All of our e*spec wheels can be used on any regular non-eBike. Wheelsets can be mixed or matched for either full 27.5+, full 29, or jump on the #mulletbus. Key Features: Axle: 110 x 15mm (Boost),Drilling: 28h,Included: Material: 6069 Aluminum, Spokes/Nipples: Custom J-bend, triple-butted spokes w/alloy nipples and nipple washers,Width: 35mm internal width.