Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number I644MMTB found under Filter Element Flui by Velcon Filters Llc. The National Stock Number assigned to this part is 2915015624887, and the Federal Supply Class is 2915 Engine Fuel System Components Aircraft And Missile Prime Movers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like I644MMTB.