A couple of years ago I was at Cabelas and bought a cheap TALL Bipod, I think that it was Caldwell.
It uses friction twist joints on the legs. The only way they are usable is if I am sitting with good back support ( like against a tree).
If I sit without support and try to lean into these at all they SLIP, and the elevation goes to h3ll!
Avoid this type of bipod or it will cost you shots....probably not on the little deer since nothing ever goes wrong shooting them.....problems always wait for the big boys as they make their own luck