Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B4-00-800 PIECE 2 found under Sleeve Directional Control Linea by Rulyn Inc. The National Stock Number assigned to this part is 4820013376937, 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 B4-00-800 PIECE 2.