What it is:

The Brass Spa Straight Mute is made of a specially designed plastic with corks  to hold the mute in the bell.

What it does:

This is the most in-tune and free blowing straight mute on the planet. The sound this mute creates is more colorful and well rounded then other straight mutes.

How it works:

The combination of the materials used and the shape of the mute's air column allow for the least amount of blowing resistance possible while keeping the center of pitch consistant.