This is a custom-made Silky trumpet mouthpiece. The base is 13A4A, with a short undercut cup (the angle from the rim to the cup is almost vertical, and the inner edge of the rim is sharp), a 29 throat (measured at approximately 27-28), and a custom specification of a backbore tighter than the 13A4A used in the 14A4A. It shows signs of use, but there is no major damage. Offered at an affordable price! First come, first served.