100% brand new and high quality Color: See pictures Use: Experiment, electronic instrument, negative ion generator,scientific production, etc.. This circuit works to produce a stable high frequency arc, high temperature, can easily ignite the fuel Size: 20x17x15mm/0.78"x0.67"x0.59" (L*W*H) The transformer is also suitable for 12V voltage, but requires increased base feedback resistor to about 150 ohms ~1.5K Omega, the resistance should be large to small replacing and adjusting, not can be too small, otherwise burn triode or transformer, also should not be too large, too large affect output or the triode tube works in non switch state and severe fever. Transformer Design for the highest output of 10KV, the maximum output of the limit shall not exceed 15KV, that is, 1.5 cm arc, the higher the output voltage is highly likely to damage the transformer. If you want to be reliable and long-term continuous work, it is recommended to use insulating wax or epoxy resin will be completely sealed, no time to seal the work of no load! No Retail Packages Quantity: 1pc Note: Due to the difference between different monitors, the picture may not reflect the actual colorof the item. Thank you!