Posey Wheelchair Wing Backs help provide firm upper trunk support for wheelchair users who need additional lateral trunk support. These lateral trunk supports are made of a 1/4 inch sturdy plywood core covered with foam padding and a vinyl cover. Wheelchair Wingbacks measure 8 inches wide by 20 inches long and are easy to install using the existing screws from the wheelchair back upholstery. To accommodate individual needs, the angle of attachment may be adjusted manually by bending the metal mounting brackets. Posey Wheelchair Wing Backs are sold as a pair.