Just need a dual head chuck for filling, also on the gauge you carry.
Either,for me, flex hose just easier to twist around. The fillers with gauge are nice as you don't need to remove, then check air with gauge. Though I still use gauge when done. Fillers Im partial to ones with pop out scale verses gauge or window.
You can get a USA made
Milton506 for 30ish
or a
HarborFreight that I picked up on impulse one day for 7.
You can spend as much or little as you want-several configurations as far as gauges. Other than recommending carrying your own gauge cause Ive found filling station gauges all over the map, is to look at the angle of dual chuck. I have one shown in pic that I use for most stuff around the house, the angle is so shallow physically cannot use inside chuck to fill on the outside dual. Id also not recommend hose extensions on truck. I used on previous MH because of the liners/hubcaps that needed removing, they are more hassle & problematic IMO than learning to seat a dual head chuck.
