The venerable King 3B is now again offered with a
.525" bore weighted nickel slide as the 2103PL, or more commonly, the 3B Plus.
It has an 8"+ (just a hair bigger) bell similar to the standard .508" bore King 3B.
However, the receiver is larger to accommodate the medium bore slide.
I believe the receiver is a part from the King 4B. For those of you
liking a heavier and more versatile instrument than the standard 3B,
this could be your ticket. This is more of a jazz horn grown up than
it is a classical horn scaled down. But it has a warm beautiful sound
for its size. Usually in stock with yellow brass bell. Includes case
and mouthpiece. Includes slide tune up.