Infiniter brand = superior performance. The choice of professional. The infiniter LR 20 green laser presenter is the eco product that offers the convenience and savings of a rechargeable battery. It is equipped with a built in usb rechargeable lithium battery which saves you money and also the environment. All the advanced features of this presenter are built into a unit with only two easy to use control buttons. You can change presentation slide pages and switch to blank screen by wireless remote control. The powerful green laser makes it suitable for large scaled conference rooms or even used for outdoor presentations. It uses 2.4 GHz fro remote control technology with direction free features and can even be used effectively without pointing at the receiver. Note: when this product is used in a small meeting room with less than 10 persons, it will be too bright and may be uncomfortable to view. Laser infiniter brand = safe, superior performance.