Review on 📏 5-Pack Bubble Level: Ideal for Building Trades, Engineering, Surveying, Metalworking and Equipment Measurement by Junior Rojas

I bought these assuming they are accurate of course. I created a stitch line for a project based on these layers. I built two separate foundation frames on posts about 12 feet apart and it was important that they were at the same elevation. Concrete poured and concrete blocks laid on the foundation. After I was done (2 full days of laying cinder block posts on each side of the gate) I checked the level again and it was way off. The? I flipped the string gauge and it was flat - I tried a second one and it was way off too. I tried the third one and it was spot on. I compared these line levels to the normal level and three were far off, ie wrong and useless. Now I have a lot of work to do to make it work. Dissatisfied. What's the hardest part about making a level?