Our patented single brake lever locks both wheels simultaneously with only light pressure, allowing for safer transfers from a non-moving chair while offering four stages of incremental braking force. These incremental stages of braking eliminate chair roll back during stable activities, without losing the ability to reposition chair in home, office or outdoor settings. This system also assists navigation of uneven surfaces, providing for easier deceleration without undue wear and tear on hands, and safer descent of hills and ramped surfaces; especially for those with limited trunk and/or upper body strength. Disc brake technology reduces wrist, elbow and shoulder pain by decreasing efforts/forces required, and reducing repetitive overuse. ADI’s patented 2-piece hub is a critical component of the system, enabling installation on most prescribed manual wheelchairs to retain quick release/removal function of the wheel during chair storage and transportation.