This is a laser pen with green,red and blue pointer of 532nm. It is perfect for teachers, students, engineers, doctors, managers and more. In addition, it is lightweight and handy, easy to carry and suitable for put in your pocket or handbags. Description: Perfect for teachers, students, engineers, doctors, managers and more. Easily to use, only need to push the button then you can see striking green beam of light shoot forth. The light can point at any targets, such as photos, blackboard, video monitors and so on. Best choice for teachers, professors, doctors, and so on. Specification: Clearly visible in the dark. Output Type :Fixed focus, continuous output and working time of over 5,000 hours Size : 14x158mm Output power: 5mWx works with 2 AAA battery (included).