Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S-143 found under Pneumatic Muffler Exhaust Intake by Air Vac Engineering Company Inc. The National Stock Number assigned to this part is 4310013399986, and the Federal Supply Class is 4310 Compressors And Vacuum Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S-143.