Lightly padded bag protects your valuable mute from dings, dents and scratches. Fits smaller bass trombone mute models. We test fit the Denis Wick red practice mute and the Best Brass practice models and they fit perfectly. Other full-sized practice mutes like the Stonelined, Jo-Ral black and Wick black should use item 133424). For mutes approximately 5.5 inches (140 mm) wide at the widest point by 9 inches (229 mm) tall. Zip-up design with a handle and a clip to attach to your case.