These are for users who need support of the head, trunk, and pelvis in order to both develop an upright sitting posture and align the head and trunk. Two sizes are available, large and small. C4 & C5 Models Corner Chair without Casters, C4, C5 Corner Chair with Casters, C4C, C5C Each is highly adjustable and available with: Chair and base Tray Abductor Padded headrests Back cushion 2? belt Optional casters.