Featuring our Patented S-Shape Seating Frame, the S-Ergo series is the original and authentic Ergonomic wheelchair in the wheelchair industry. Aircraft grade aluminum is the primary frame material which boasts a limited lifetime warranty, and 1 year on parts. The S-Ergo series feature Ergonomic design on the seat, backrest, armpads, brake handles, and handrims. S-305 series specifically feature removable and height adjustable footrest, breathable seat and back mesh upholstery, removable seat and back cushions, push to lock brakes with built in 2" extension, Quick release rear wheels, seat and armpad height adjustable, and a super compact folding frame for ease of travelling.