Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8770257-5 found under Tubing Assembly by Spencer Industries Inc. The National Stock Number assigned to this part is 4720009248524, 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 8770257-5.