Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 990-HP F NO 11 found under Helmet Welders by Fibre Metal Products Co The. The National Stock Number assigned to this part is 4240013594931, and the Federal Supply Class is 4240 Safety And Rescue Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 990-HP F NO 11.