I don’t have a GFX, but I believe it has the same strap lugs used by Hasselblad on their V system cameras. I’ve used and loved the newer style Hasselblad nylon strap with my 500CM for years and wish I could use it with other cameras. It has rubber strips interwoven with the nylon (very similar to Domke straps) so it doesn’t slide off your shoulder, ever. It isn’t quite as fashionable as some of the artisan and esoteric straps out there, but it is high quality and incredibly functional, and fairly cheap. I think I paid about $40 for mine and I have seen them for much less on the auction site.