NEC 5U4GB vintage rectifier tube. Functionality confirmed in an amplifier (operates normally). Sound output and power-up are both problem-free, and the condition is good for its age. Selling to organize my collection. • Manufacturer: NEC • Model: 5U4GB • Type: Rectifier Tube • Condition: Works well, confirmed • Appearance: Please check the photos • Accessories: None (tube only) *Please understand that this is a used vintage item, so only those who understand minor scratches, etc., are welcome to purchase. *Returns are not accepted to prevent product substitution.