Jemini Medium Back Draughtsman Chair Adjustable D-Kit Charcoal KF822471. Fully upholstered seat/back. PCB Mechanism. Max Weight: 18 stone. Usage Time: Up to 8 hours. Seat Dimension (WxD): 480x460mm. Back Dimension (WxH): 420x400mm. Seat Height: 580-830mm.