Are you talking about
L'Orange V1, which looks to me like your average portable pump head, that you unscrew the grey thing and pull out and reverse the inner bits to go between presta/schraeder?
I've got
L'Orange V2, the chuck is a completely different design, the pictures don't make it totally obvious, but in the last picture you can see the presta hole, and exposed threads; what you can't see is the schraeder head on the inside, screwed in by its threads; you just unscrew the whole thing, flip it, and screw it in the other way to switch valve types.