This is a set of five 12RHH14 9-pin miniature composite tubes made by NEC. These are rare vacuum tubes that were used as video output tubes in old TVs, but some people also use them for making their own amplifiers. This time, we are selling them as a set of five due to inventory clearance. ✅ Report of Simple Inspection (Tester Check) Results We do not own a dedicated vacuum tube tester, but before listing, we performed a basic continuity check (tester check) on all tubes and confirmed that there were no defects in the following items. [Confirmed by Simple Inspection] No filament (heater) breakage: We have confirmed the resistance value (continuity) between the heater electrodes (pins 4, 5, and 9). No short circuit between electrodes: We have confirmed that there are no short circuits (continuity due to contact) between the heater electrodes (pins 4, 5, and 9) and all other electrodes involved in amplification (plate, grid, cathode, etc.). ☆ Notes on purchasing (please read carefully) This product has not been measured for "emission capability (actual value)" or "amplification factor (Gm)" using a dedicated vacuum tube tester. The tester check is only a simple inspection and does not completely guarantee the operation in actual equipment. Please bid only if you understand that this is a "as-is" sale, as these are vintage parts that have been manufactured many years ago. ☆ Product Details Model number: 12RHH14 Brand: NEC Quantity: 5 Condition: Unused dead stock, or near-new condition (※ Please check the condition of the original box in the images)