I'm thinking about getting them from this site: Bottom Caps : Pickett Brass, Unique accessories for your trumpet I don't know whether I should go for the Cylander ones or the Barrel ones. Here's the options I'm thinking of: Trumpet Model: Yahama Xeno C/Bb Valve Cap Weight: Heavy (0.75) Include bottom cap o-ring: Yes Plating: Gold Plated Finish: Polished 4 Valve: No I'm was wonder what your opinions are on this. I play an Xeno and I like the heavy sound it produces and want to increase that sound even more. I was wondering what the different weights are and what the measurement units were. Thanks.