Superior medium-Mu Twin Triode for use in preamplifier and driver circuits. Standard replacement for all circuits requiring 12AU7/ECC82 types. • Low microphonics, high linearity • Reproduction of the NOS GE 6189 • ECC82 equivalent Electro-Harmonix tubes are all new designs and are of excellent quality. Many OEMs use relabeled Electro-Harmonix vacuum tubes in their amplifiers. If you want great sounding tubes at a very reasonable price, then Electro-Harmonix tubes should be on your list. Tube Specs: https://shop.ehx.com/catalog/addimages/12au7eh.pdf