I have the Viair 400P. Works well to top off the tires. I have G614's and keep 105psi in them. One rim has had leaking problem when cold. It would loose 10psi over night. This is a problem that I finally fixed. The pump gets warm, but not hot to go from 95 to 105 psi. To consolidate space, I made a battery box from a plastic vinyl record storage box that holds the two batteries. The top locks and opens easy so I can use the fifth wheels batteries to run the air pump. I chose to make an extension cord for it instead of getting a longer air hose. So everything fits into the caring bag it comes with. I used Anderson Power Products connectors to make the extension. Lighter and easier to store then air hose.