Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number FD SEMIRIGID FLEXPROBE XLS5 found under Probe Fiber Optic by Thermo Scientific Portable. The National Stock Number assigned to this part is 6665015597647, 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 FD SEMIRIGID FLEXPROBE XLS5.