Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RB9543-3 found under Hose Air Duct by R And B Electronics Inc. The National Stock Number assigned to this part is 4720014459426, and the Federal Supply Class is 4720 Hose And Flexible Tubing. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like RB9543-3.