The Adams F3 flugelhorn features the F2 (heavier bronze) valve block. It has a bell that is slightly larger in diameter than the F2 (it is a bit over 170mm), and it also has a larger bell throat. The branch has a slightly tighter wrap, and you'll notice there's no brace between the branch and the bell, ensuring more resonance. The soldered bell lead provides extra core to the sound. This is the darkest flugel we make and has a velvety, chocolatey rich sound. It has an amazing tone quality and ease of playability.