The very light, ergonomically shaped back shell is available in two different contour depths of 30 and 50 mm. The backrest consists of a concave aluminium shell, a cushion and a cover made of breathable fabric (spacer fabric). The backrest consists of a concave aluminium shell, a cushion and a cover made of breathable fabric (spacer fabric). The semi-circular shape of the backrest plate allows the backrest to be fitted perfectly between the backrest tubes of the wheelchair.