Do you fill air tanks?

“We can fill High Pressure Air (HPA) tanks
We can fill most HPA tanks of all sizes up to 4500 PSI, larger tanks should be left overnight to allow cooling time between fills (air losses pressure as it cools).
We do not have the necessary equipment to fill Co2 tanks. Co2 tanks cannot be filled with compressed air like a HPA tank.
You can usually tell if you have a HPA of Co2 tank by looking at the area below the threads that screw onto the gun. HPA tanks usually have a gauge showing how much pressure is inside and a fill nipple, while Co2 tanks typically have a single blow off valve.”