80 Cubic inch HPA tanks are one of the most common tank sizes for back players and players who need to have a little bit extra air on the field. These are very similarly sized to 77ci, which is about the same length as older 68ci tanks (before the sizing changed), so they fit very comfortably for most players that have been around for a while. These 80ci/4500psi tanks are designed by a variety of manufacturers so regulators, designs, and specs will vary from tank to tank.