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.

The level fits a standard size hot shoe and I believe the sony hot shoe, though referred to as a multi interfaceshoe , has the same dimensions as a std hot shoe - I think it conforms to the ISA std. The sony multi interfaceshoe just has it's connections hidden at the inner front of the shoe. I purchased this level for a Canon HV20HDV Video camera which has it's hot shoe contacts hidden, similar to your Sony and it fit just fine. Hopethis helps. Bill