Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4 331AP1 found under Latch Interlock Doo by Otis Elevator Co. The National Stock Number assigned to this part is 5340004222792, and the Federal Supply Class is 5340 Hardware Commercial. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4 331AP1.