Check the listing for details. Mberg lup.X Double Bass Wolf Tone Eliminator - 30g. Condition: New. Listed at 27.95 USD. Bid Farewell to Unwanted Wolf Tones in Style Are you finding that wolf tones have become a pesky problem during your practice and performance sessions? Mberg developed the lup.X Wolf Tone Eliminator to combat these unwanted resonant frequencies with almost no dampening effect. Say goodbye to wolf tones without saying goodbye to the full, rich, and resonant capabilities of your instrument. Easily mount and adjust the rubber-free lup.X Double Bass Wolf Tone Eliminator until it performs to your specifications. Plus, with its sleek brass finish, this product will add a complementary elegance to your instrument. Orchestral musicians at Sweetwater love how simple the lup.X makes eliminating wolf tones in their music!Easy to use To use the lup.