I’ve started learning piccolo trumpet, what mouthpiece should I start with?

Edited

When beginning to learn the piccolo trumpet you need to start with a moderately sized mouthpiece.  The 5D, or 7D would be very a popular middle of the road options to start working on piccolo trumpet. 

At first we do not recommend using a large diameter such as a 1.5D, or a much more narrow option similar to a 10D.  These options may work for the seasoned musician, but at first stick with a 5D, or 7D and find what works best for you.