Last year we heard about the GRIT Freedom Chair, an off-road wheelchair that users propel using arm levers instead of hand rims on the wheels ... such as knobby tires, a Rock Shox air suspension ...

Not according to husband-and-wife team Zack and Cambry Nelson, who are now marketing their off-road motorized "wheelchair ... inch-wide fatbike tires on each of its four wheels.

Most days, he can be found in his workshop in Kilifi with his team, piecing together tires ... the wheels are independent, that means that the user can go over rocks and logs and the wheelchair ...