Adjustable legs for anything with 2020 or 2040 extruded bars. One part is designed to attach to the rail using two M5 screws and T-nuts per leg. The other two parts can be stacked like legos and secured at the desired length with M5 screws or smaller screws with the appropriated thread insert.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/4DBwA2vnvuM