The CycleOps Aluminium Rollers feature durable steel-frame construction that meets the needs of the most demanding cyclists. See your fitness-and your bike handling skills-improve when you add CycleOps rollers to your training program. You′ll increase your balance, control and ability to ride a straight line, all of which translate to more efficiency, power and technique on the road. An adjustable belt for right and left dismount that gives you added flexibility. And a bi-fold design that makes storage and transport a snap. The 3.25-3.5" precision lathed drum diameters offer an optimal range of resistance with a super smooth ride and the adjustable wheel base fits just about any size bike. Rubber foot pads ensure that the only thing moving on the rollers are the drums so you get a secure, sturdy ride. Because mastering the rollers can take a few tries, the 16" wide base gives you room to move around until you′re holding a straight line like never before.