Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 57A4248A7075 found under Test Block Ultrasonic by Olympus Ndt Ne Inc. The National Stock Number assigned to this part is 6635000220368, 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 57A4248A7075.