https://www.laser-level.co.uk/
Just remember your concrete is only going to be as good as your setting out so get a half decent one
You can see my red laser and receive it up to 350 metres. Didn't get on at all well with the green one. Didn't go as far and found it harder to see when you loose the signal when working near eye line.
You can see your laser without a receiver at 350m?!
Only looking straight at the lense at eye level. Just a red flash but gives a reference point when taking levels the old fashioned way!