The 2.25" diameter drums of the Kreitler Alloy 2.25 Rollers provide the greatest resistance of any Kreitler unit simply because they have the smallest diameter. They're ideal for super fit riders who love to punish themselves when training indoors.
Like the Alloy 3.0 Rollers, these are built with modular technology so they're compatible with the Killer Headwind fan unit. That said, you'd have to be a beast to need it. One important benefit of the smaller drums is that they're lighter, and this unit is more compact and portable than the 3.0 rollers. All Kreitler Rollers have a lifetime warranty.