Code 8540 79 000
OTHER MICROWAVE TUBES, EXCEPT LAMPS WITH A CONTROL GRID
SECTION XVI. Machinery and mechanical appliances; electrical equipment; parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers, and parts and accessories of such articles
microwave tubes (for example, magnetrons, klystrons, traveling wave tubes, carcinotrons), excluding grid-controlled tube: