laser land levelling is a precision land lecling tecnology..
Precision land leveling (PLL) is a mechanical process of grading and smoothing the land to a precise and uniform plane surface at grade or no grade (zero slope) with variation of less than 2cm. The LASER technology has proved to be a highly efficient tool for achieving a high degree of precision for carrying out PLL operations in much lesser time.

parts :-

1-laser recevier

2-laser beam

3-laser transmitter

complete system of laser land levellinf

operation system

transmeter

transmeter

Back view

parts of laser land levelling 

a complete figure of laser land levelling