Great concept, two for one, a Rovner dark with added mass or a hybrid lig with metal on the reed. In practise, slightly better than a normal Mk3 and eaten up by a Vandoren optimum (at much greater expense). Metal cradle slips on the reed easily when fitting the mouthpiece to the neck cork. IMHO not better enough to keep if you already have the other ligs - otherwise it is good value. It may also do better on other reeds/mouthpieces.