For three years I have been working almost daily with a Bosch Cross Line Laser. What was it like before? Cruel: with spirit level and folding rule on a ladder Balancing I often just "trying" the holes for Bring cornices on one level. The results were often from the department "lopsided and crooked". Today: telescopic rod with the mounted Cross laser between floor and ceiling clamps, laser to align height and it can (not to peek!) is running laser loose flaky on the projected line to work along. The black rubber cap Deckenklemmung I covered with a white sock - then the Ceiling not marred by black imprints. Thank Bosch!