These torpedo stages are terrible! One has a magic moving bubble on an almost horizontal surface. They copy a very popular brand I had before. There are serious quality control issues with displaying horizontal planes correctly. If you flip the same layer to the other horizontal side, you get a completely different meaning! This is true for both the green and white values I got, with the white being worse as shown in the video. No magic, I just flip them both over to the other side. The bubbles move non-randomly from time to time, and dirt floats in a vial on the green level. The only bubbles that were correct and consistent were the vertical ones. I could flip it vertically to either side and the readings would be identical for both samples I received. I didn't bother to test the 45 degree bubbles because it just wasn't worth it as they are useless. The aluminum rails dangle and move along with very sharp burr edges where they meet the plastic body. There are two in the set, choose the best that's acceptable for use, but I'll stick with the good levels I know.