Apollo Command and Service Module nitrogen tetroxide valve assembly made by Simmons Precision Products of Yorktown, New York, measuring approximately 16″ x 12″ x 5.5″, with the side reading: "Valve Assembly, Nitrogen Tetroxide…Contract No. NAS 9-150, Serial No. OS275NTV6080." The Apollo CSM used Nitrogen Textroxide (N2O4) as an oxidizer, in combination with Monomethyl Hydrazine (MMH) as a fuel to power the Command Modules SE-8 and Service Modules R-4D attitude control engines. In very good to fine condition, with heavy denting to the end caps.