That is the one!.......remove the base and that is what I used. I haven't found another here yet, but when I do its going to get a trial run.
Whaddya think? right concept for beating cant and inclined shots in one unit?
This one could possibly be used on something like the "Daystate" electronic air rifles.
I agree a level to reduce/eliminate cant is quite important. I've trained with one and competed leaving it off, and yes uneven ground or leaning targets can throw you off a bit. The biggest trouble I have is getting any level device mounted at a correct focal length for my eye (need reading glasses now) so for a while it was mounted on the silencer out past the windithingy......useful with left eye open when taking the shot. Only problem was putting the rifle away in the case I had to remove it.
Simple and unobtrusive would be best I think. Waterproof too as mentioned.......