The Nexus is fitted with a rotation mouthpiece so you can position it perfectly for maximum comfort. It also has an angled purge valve to divert bubbles out of the ling of sight. The oval shape of the upper tube minimizes drag and allows a lot of air to flow. It is also flexible, so you don't want to hang the Nexus from your mask strap, you can fold it up and stow it in a BCD pocket.