Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 42AB found under Bonnet Valve by Dynatech Co. The National Stock Number assigned to this part is 4820000968864, 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 42AB.