The indication of battery life is rather random: We quickly pass a minimum while the batteries are 1.5V. The timer function is not practical to use, and ultimately holds the gadget. The "black screen" button does not work, and I realized messuis to use the green laser remote pourvait be less powerful than red laser pointers autonomous. Finally, three months after the end of guarantee, the laser shows signs of weakness Its strength remains to operate without driver installation ... But others know also do it for less.