MagicWheels Geared Wheelchair Wheels are manual wheelchair wheels with a geared hub that reportedly provides a 2:1 mechanical advantage and an automatic hill-holder. Similar to bicycle technology, the 2:1 gear requires significantly less arm strength to ascend inclines, negotiate uneven terrain, control descent, and bring to a stop. The hill-holder prevents the chair from rolling backwards and allows the user to ascend hills/ramps at his own speed and rest when needed. Shifting between the 2:1 gear and the 1:1 gear (for flat-surface transport) requires only the palm of the hand. MagicWheels is compatible with most makes of chairs and adds no extra width to a chair.