Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4500-B-6 found under Fifth Wheel Assembl by Holland Usa Inc. The National Stock Number assigned to this part is 2510010180654, and the Federal Supply Class is 2510 Vehicular Cab Body And Frame Structural Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4500-B-6.