Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1516DG-1A-2.5F found under Gage Differential Dial Indicatin by Orange Researchinc. The National Stock Number assigned to this part is 6685011323343, 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 1516DG-1A-2.5F.