I pretty much suck at guessing anything past point blank range!! I have the range finder mount on my Vortex, but it is for my video camera and not a range finder. I would think any of the flat style will work, but thats only a guess. I have a Nikon 440 and it works pretty good for me but the low light ranging is what is hard to do. But my 440 is a upright style and would be harder to put on a RF mount.