FirstClass® Adjustable Seat The new FirstClass® Heavy-Duty adjustable seating system base is constructed primarily of a square steel tube frame. It features replaceable stainless steel leg rests sockets and multiple mounting systems for seating position, height, and angle. The seat back features multi mount positions; push handles, heights from 14 to 20 inches, and adjustable back angles from 90 to 115 degrees. The basic structure of the seat back is high-strength aluminum. The flip-up and lock-down armrest assemblies are principally thick aircraft alloy aluminum plate and bolt on to the lower frame. Armrest pad mounting brackets are available in heights from 8 to 12 inches.. FirstClass® Adjustable Seating System: Plug In Adjustable Armrests Standard Heavy Duty Legrest Hangers Standard Heavy Duty Extension Tubes w/Footplates Standard Solid Seat Platform Standard Adjustable Hip Angle Standard Adjustable Frame for Width & Depth Standard Sling Back Standard 360 lb. Capacity Standard