The Warburton system lets you choose a combination of rim diameter, cup style and depth, with a backbore to best balance your sound and resistance. This flexibility means you can have the most efficient mouthpiece with which to perform in any given playing situation.
Our two-piece system consists of fully interchangeable "TOP" sections and "BACKBORE" sections. Due to the many demands placed upon the modern brass player, the variety of Warburton cup designs are able to produce the most desired sound in any playing idiom.
The Warburton system allows the player the opportunity to personally "balance" their equipment. This can now be accomplished without the necessity of traveling to a mouthpiece maker or waiting for a mail-order custom made piece that often does not work and cannot be exchanged.
More info can be found here: http://www.warburton-usa.com/index.php/trumpet-cornet-and-flugelhorn-mouthpieces#tops
$115 + Shipping