Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 77553-78X16 PIECE 17 found under Pad Bearing by Electric Boat Corporation. The National Stock Number assigned to this part is 4820012058387, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 77553-78X16 PIECE 17.