Do not buy cheap lasers!
There are low-cost lasers on the market today that could pose serious risk to your students due to a lack of infrared (IR) filters. Even pointers that use IR filtering could still be harmful, due to shoddy manufacturing that provides poor conversion efficiency (when converting from infra red to visible light). While all lasers should be handled carefully to prevent users from harm and should never be pointed at unprotected eyeballs, these lower cost lasers are particularly problematic in the academic atmosphere where there are many people in close proximity. For the safety of your students, please always make sure you have taken all the proper precautions possible, including the use of effective IR filtering. Products being sold are not toys. They are for Educational / Laboratory use only. They are not for use by children 12 and under.Well, i have made many times test of lasers before i came across apc green laser pointer. this is very special laser http://www.buylaserpointer.com/green-laser/p-25.html I purchased it on this website.