Silver plated. 25.50mm cup diameter with a 0.232" throat bore. The Griego small shank 5GM has a 5 rim with a cup that is in between a 5 and a 6.5. Perfect for the high player that needs a little more embouchure room but wants the shallower cup. Sleek "Deco" style exterior is heavier than traditional models, allowing for a darker, more focused sound.