The innovative DT-200 Series are the world’s first waterproof and dustproof digital theodolites. They can stand up to any "wet-weather" or dust condition in the field (DT-205/207/209 based on IP-66). The benefit is that you will experience no downtime on the job due to inclement weather. Topcon's DT-200 Series comes in two variations: The standard DT-200 and the deluxe DT-200L with an additional laser for precision aiming.