PE experiments? Plastic water bottle?

Friends, Have some exercise ,of stretching with use ,plastic water bottle, one day a friend of mine, spoke that it invented this, how can i make this exercise,it explained , but i did not understand nothing, have some photo here, comments welcome.

I have no idea what you just said, but, you can use a plastic bottle filled with warm water to warm up but it’s not really an exercise. Although, I have heard of people using bottles for fulcrum stretches, the A-stretch for example.