Trombone mouthpiece received from a certain musical instrument manufacturer. Based on its design, I believe it's a prototype of Yamaha's first mouthpiece. The size is marked as "48," which is a Yamaha-specific size not found in the Silky lineup, which Yamaha was using as a model at the time. Like Silky, it has a long shank, with a total length of 8.5 cm and a weight of 186g. For large bore trombones. Used. I've removed the surface deterioration caused by aging to this extent, but please refrain from purchasing if you are concerned. Please check the condition of the item in the photos. #Trombone #Mouthpiece #YAMAHA #Yamaha #Prototype #Prototype #Vintage #Vintage