Vello Two-Axis Hot-Shoe Bubble Level

Yes, the Vello Two-Axis Hot-Shoe Bubble Level will fit the hot shoe of the GFX system cameras.

this one fits super nice on my gh-5, will grab some more as soon as they go on sale!

i thought Hot shoe were standard sizes and i assume that it will otherwise 3rd party flash manufacturers would not be able to sell flashes

I can't imagine why it wouldn't. It just needs to slide into the hotshoe. It fits my Sony cameras no problem. Sometimes I also just drop it onto the LCD when doing and overhead shot. Generally, just super handy to have a small level you can use on the hotshoe or on the camera itself.

I, too, have no idea what the liquid is. I did like the responder citing spirit levels.. I bought it because my camera base covered the level on my tripod head. I like the way it works on the hot shoe....

Make sure you buy the newer water tight version. First generation isnt; once water gets in, the air bubble disappears, and it no longer gives an accurate reading.

I think it would fit. I bought one for my Panasonic micro four thirds and found out that the camera shows you the horizon line. In fact I havent used it yet and dont need it for the pictures I take. Maybe it is very good for a special kind of photography, but I dont know which one It is. I dont think it is a practicall accesorie