Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 71601 31 found under Sizing Tool by Avon Protection Systems Inc. The National Stock Number assigned to this part is 4240016170815, 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 71601 31.