When users are making decisions to use laser tech supported green laser alignment to make line projection, users have also noticed that there are also other choices such as red, blue, blue violet and infrared laser alignments available for users to make line projection on required working fields. For instance, users are able to make line projection with a red laser alignment, but it is not visible enough when users are making long distance line measurement. 532nm green laser has shorter wavelength than 650nm red laser, thus it is able to project more sensitive and more visible green color laser light in distance. In addition, green color laser light is also the most sensitive color laser to human eyes, thus it can the easiest absorbed laser color in projection. When the targeting distance is super long, 532nm green dot laser alignment is just the best choice to help users to get the most precise and accurate dot projection at allowing targeting distance.