Bubbles are perfectly visible, even from a sharp angle. Mark-out lines without needing to stop due to an end-to-end casing. Linear scale positions to measure in comfort, even when viewing from above. The variable distance marks for up to 4 flush socket boxes bring another advantage to electrical installation work. Sliding marking points for boxes allow the spirit level to be adjusted to the marking distances required by local regulations. Can be used in a wide variety of situations, even on an international level. Ideal for portable use and storing away.