Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21504-00-20-05-02 found under Probe Proximity by Bently Pressurized Bearing Company. The National Stock Number assigned to this part is 6685013386130, 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 21504-00-20-05-02.