Matched set of 4. Compact small bottle version of the Groove Tubes 6L6C. Inspired by the original Tung-Sol and GE made 5881 JAN spec military design tubes. The compact design changes the resonance and has a better fat and round tone than the 6L6C. It also fits into many amps that were designed to use a small bottle tube. Normal performance, best for all-around tone.