Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B615-21 found under Lens Telemeter by L3 Communications Corp. The National Stock Number assigned to this part is 6210009662586, and the Federal Supply Class is 6210 Indoor And Outdoor Electrical Lighting Fixtures. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B615-21.