Tired of having horizontal boost blocks killing mario when he crashes into a wall? Worry no more! Unlike Jhonwil's stop block (which runs the stop code every frame when Mario is touching it), this will only stop Mario if he is going too fast (if value between #$35-#$CA, faster than Mario's max running speed). This is useful for preventing Mario from dying when he runs into a wall very fast.
This version is actually the "wall" part, unlike the previous one, which is the "air" tile next to it.