Tested. 3x RCA 1x ITT 1x Dumont Specific preference if you have a choice in the buyer notes. The product is a vintage RCA Dumont 6AT6 vacuum tube electronic valve, tested and new. This stereo part is a valuable addition for those looking to enhance their vintage audio and video equipment with reliable and authentic components from trusted brands like RCA. Its high-quality construction and testing ensure a smooth and enjoyable audio experience for collectors and enthusiasts alike.