This is being used as a case for my Melton HOJO Gravity 2011FA Bb tuba. The instrument fits very snuggly and gives far more protection than the soft gig bag that the instrument is supplied with especially as the front action valves stick out on their own. One velcro strap keeps the tuba in place until the case is closed, at which point the foam interior holds it securely. There are two holes for mouthpieces which are held in place when the lid is shut. The catches and wheels have worked OK so far. Although solid, the added weight of a hard case still allows for lifting into the back of a vehicle.