I installed a huma reg on my prod. My pressure guage now shows only the reg pressure. So I do not know when it is low until it go past the set reg. I found a front gauge by huma for the marauder rifle. It is exactly what I need to install on my prod so I can have a tank guage and reg gauge. Except huma only make it for the marauder rifle. Anyone know if there is one made for the marauder pistol? I can't find it anywhere. Can't believe they made one for the rifle and not the pistol. ;(