Exhaust disc valve The blades of FK-9 disk shaped diffuser are disk-like structure, and its blow-out air is hard for deceler Exhaust disc valve- Made of aluminium, Rustproof - Removable Core - With Collars - 5 Sizes, 100, 125,150, 160, 200 - Powder Coated, Standard Color RAL 9010/9016, other Colors Available