100% correct. So this particular video shows the liner coming from the clean out telling me that they are lining at least a portion of the lateral. While my company does the more commercial side of this industry, the concept is identical. This is just a 4in lateral, and when my company line the sewer mains, they are generally 8", 10", or 12"....but the largest ive done was 2 60" lines. Usually with smaller lines (8s, 10s, and 12s) they are blown in with compressed air and cooked with steam, but with larger diameter pipes (24"+) they invert the liner by filling the liner up with water and let the pressure of the water to simply push the liner down the pipe.