Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 16F-CB2 4.00IN PIECE 11 found under O Ring by Newmans Inc. The National Stock Number assigned to this part is 5331014399261, 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 16F-CB2 4.00IN PIECE 11.