Eurotubes &ldquo;EuroDamper&rdquo; Tube Damper Rings for Dual Triode Preamp Tubes and EL84 Power Tubes. Set of 4. Custom made from special soft durometer hi-temp silicone These will reduce or eliminate tube rattle in most all combo amps For all 12AX7, 12AT7, 12AU7, 12BH7 Pres and EL84 power tubes Largest and most effective vacuum tube dampers made