According to different requirement from different users, this green line laser alignment is always required to project different size of green reference line with various line length, line width and operating distance. As a result, laser tech experts have designed this alignment laser with different laser line length and line degree range from 5mW until 100mW. Once the targeting distance is very long, users are recommended to choose high powered alignment laser in order to get ideal line projection result. Usually low powered 5mW green laser alignment is used in room line measurement occasions. Within 3 meters working distance, this line projecting laser gadget can project long green reference line with length range from 5 meters to 6 meters. If the operating environment is very dark, the projecting green reference line can reach as long as 8 meters. If users are not very familiar with this kind of laser tech supported line measurement tool, it is very important to make perfect communication with laser experts before making a decision to purchase this line measuring laser alignment.