Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SPA-USMC4X25 found under by S P A Simrad Inc. The National Stock Number assigned to this part is 5305015377539, and the Federal Supply Class is 5305 Screws. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like SPA-USMC4X25.