The Impulse series are by far the most durable and reliable laser rangefinders available. All these lasers are specifically designed for optimal performance under any condition you may encounter in the field, because the all-aluminum housing is extremely rugged and completely waterproof. No other laser in the world can hold up to harsh conditions like the Impulse. Most of the Impulse models come with onboard solutions for height, horizontal and vertical distance, distance between two in-line objects and cumulative distance for perimeter measurements. Some models solely measure slope distance but are still able to lock onto far away targets that other rangefinders can't even dream of. You can use these lasers as a handheld unit or mount them on a tripod for added stability. They can also be integrated with LTI's MapStar modules and provide three-dimensional measurement capabilities.
Depending upon your specific use will ultimately depend upon what model will best fit your needs. The standard models come equipped with a red-dot scope that has no magnification, but you can easily upgrade to a 1.5-4x power scope if that makes better sense for your application. Check out all the models and use the comparison chart to quickly decipher the difference between them.