Things to look for in a good laser level include range, accuracy, long battery life, durability and mounting choices. A strong light beam, warranty, self-leveling capability, out-of-level indicator and being able to do vertical lines are very useful. The best laser levels provide consistently accurate results and do so as often as required. A tough, durable and waterproof exterior is an advantage, especially if the laser level is for construction.
The choice of laser level is influenced by the amount of use, the type of jobs it is being used for, and the accuracy required. There are different requirements for engineers and builders than for hobbyists, and the prices vary accordingly. Ideally, the laser level should have a variety of mounting options and is not only tripod mountable but has a built-in mount, magnetic mount and clamp mount. These choice of mounts enable the laser level to do its job in most conditions, including tight spaces, indoors or outdoors.
The best lasers have a light beam strong enough to use outdoors in daylight. This eliminates the need to use more sophisticated instruments that require two people to do the measurements or layout. The big advantage of a laser level is that it can be operated by one person.
Another useful property is to have a laser that produces more than one beam so that different tasks in a job can be lined up. Finally, it is nice to have an operator manual and good technical support available. If there are any technical issues, getting technical support with ease is key.