Here ya go. It's a piece of bird netting stretched between two posts. One side of the netting is attached to a wooden stake, the other side is permanently affixed to the metal stake closest to the camera.
When it's closed/in place, a wire loop attached to the post closest to the greenhouse holds the wooden stake in place. There's also a wire loop at the base of this metal post.
Here it is open. We just lay the stake on the ground while we're working in the garden. For something so simple, it was hard to describe! LMK if you have any questions.