I used this level on a 10 x 10 foot floor for a farm building. The floor must be perfectly level. It would cost a lot more to achieve that kind of accuracy at an electronic level. This block is simple and effective, but I'd rather have a second valve on the other end. Anyway, I used the built in garden hose valve so there was no problem. I used a homemade version of this level when setting the levels for many of the dots in the footer fill and while it worked, this module would have made the job a lot easier.