Review on Building Engineering Surveying Metalworking Equipment by John Swain

I really wanted to like this pack but you can't trust them. From the package there was only one on the plane. One was almost completely out of the way. After sitting on the level counter for several hours, two were level and two near, but when I put them in my bag to take outside and then returned them after work outside, they were back out. I don't understand why they settle when sealed. I can't trust them, so I'm sending them back.