Mercer & Barker GW3 mouthpiece used RRP £150. Purchased at the end of 2025 but hardly used I personally prefer a size 4 mouthpiece. There is the usual mark where it has been inserted into the euphonium and inside the stem there are a couple of tiny lines of discoloration presumably there from manufacture. Cup is perfect condition and can’t emphasise more that if used more than 3 or 4 times I would be surprised. Cup is 26.4mm throat 7.48mm and rim 6.5mm
