SLOKER TENOR TROMBONE 1A Gold Plated Finish Mouthpiece for Large Bore Trombone Inner Rim Diameter: 25.5mm Throat: 6.5mm Comparable to a 6 1/2 or 5G Supervised by Branimir Slokar Old models in good condition are considered valuable. This is a one-piece design, not the current rim-change type. Although designed for tenor-bass trombones, it can of course be used on tenor trombones if they have a large bore. The condition is considered to be quite good. I understand that there are very slight scratches on the shank from being test-played a few times after purchase.