New Sensor (NS, Inc), which has SOVTEK and Electro-Harmonix brands, has reissued the TUNG-SOL vacuum tube. TUNG-SOL introduced to the world in 1954, 5881 has a huge impact on audio and guitar amplifiers, etc. And this original TUNG-SOL 5881 became one of the most popular names in the 1950s. NS Company plans and designs TUNG-SOL brand vacuum tubing to be highly reliable and warm vacuum tubing in all output areas. The TUNG-SOL vacuum tubing can be purchased here, is adequately aged with domestic automatic sorting machines, and it will get a good output from use. Country of Manufacture: Russia. Other than the electrical characteristics of the product (damage to other devices, bulb tilt, valve height, logo missing, etc.) are not covered under the warranty.