Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 553-3X4 found under Screw Leveling by Leica Geosystems Inc. The National Stock Number assigned to this part is 5305003789542, 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 553-3X4.