For 26", 27.5" (650B) & 700c wheels with disc brakes A wrap-around seat structure creates a virtual cocoon of protection and features an updated shoulder harness with a multiple height adjustment system. An innovative suspension system cushions bumps and jolts and the integrated roll bar provides extra head protection and doubles as a carrying handle. Adjustable footrests and straps keep small feet away from spinning wheels. Child seat complies with stringent European, CPSIA and Proposition 65 safety standards. The included heavy-duty disc mount rack features an innovative BabySeat™ attachment that requires no tools to attach and remove seat from rack. Once the seat is removed, the exposed QuickTrack® system is compatible with all Topeak MTX TrunkBags and MTX Rear Baskets.