Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 75.0400 found under Iris Diaphragm Optical Instrumen by Rolyn Optics Co. The National Stock Number assigned to this part is 6650011148586, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 75.0400.