Projects a high intensity visible bright green beam， 532 wavelength.Requires two AAA batteries (not included).Power output: <1mW.Created using heavy duty durable materials.Color of Beam: GreenBody Color: BlackNotes:1.Please don't keep open for a long time， otherwise easy to damage the light bulb2.Please adjust the focal ，and then match at a distance of approximately 5-7cm from lamp holder，and at the most thin part of the light.3.Very Important: this laser's electrode is opposite，please put the battery in opposite directionNever point it to eyes!!! Keep it away from children!!!The green laser pointers are brighter.The human eye is more sensitive to green color and this laser pointer is much more noticeable than other light color， so this pointer is the perfect tool for astronomers， lectures， etc.Use your laser pointer to point at any desired targets on projection screens， video monitors， presentation graphics and more.Best suitable kit for professors， teachers， doctors， student presentation and etcIt is great for astronomy to be used point and locate the stars and also comes in handy for builders and architects to point at objects on the site from a distance