We have sold 32 of these things and I have no idea what they do.
“The “cutting edge” and the impact surface of the handle are equipped with a rugged, wear-resistant surface that can be marked with the included blue and red pens (commercial lipstick can be used as an alternative).”
Because you’re untrained.
This should help:
Unfortunately, the trainer doesn’t hold juice. After just a few hours of concealed draw, the glued on end felt came right off, and half of the stitching from the main portion began coming undone. Nice little trainers, but the felt needs much work.