Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B56-72 found under Switch Rotary by Aeroflex Weinschel Inc. The National Stock Number assigned to this part is 5930010783533, and the Federal Supply Class is 5930 Switches. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B56-72.