Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 70501 157 found under Lens Facepiece Chemical Biologic by Avon Protection Systems Inc. The National Stock Number assigned to this part is 4240015660873, 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 70501 157.