Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 333-3171 PARTS KIT C found under Parts Kit Cleaner Ultrasonic by Blackstoneney Ultrasonics Inc. The National Stock Number assigned to this part is 6545013399489, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 333-3171 PARTS KIT C.