- Brand: Bruno Tilz - Model Name: baco - Material: Brass, Silver Plated - - Condition: Lightly Used (Comes with original box) Thank you for viewing. This is a center model bass trombone mouthpiece, a 1 1/2 by Tilz. It's in beautiful condition with almost no scratches. Rim inner diameter is 27mm, throat diameter is 7.2mm. The tone is soft and doesn't break up. It would likely pair well with European instruments. The response is quick, and it's a good piece for those who don't want a heavy tone.