Fantastic comfort grip; Built-in lithium battery, rechargeable via a USB port, thus ensuring it is environmentally friendly. Output power: Class IIIa, output power is less than 5mW, eye safe laser product.nWith dual color LED indicators, LED will change from red to green when charging is completed.nIf the battery power is running out, the Red LED will be flashing as a warning to save power. It can also cut off the power automatically if the user forgets to turn off the unit.nThe presentation can be made on an LCD display or a projection wall TV.nCan easily remote control the mouse for a distance up to more than 15 meters in open space. Apply the 2.4G RF direction-free remote control technology and this unit can be operated without aiming at the receiver.nInfiniter 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.