Logitech R800 Pro Presentation Remote with LCD Display for time tracking

Laser Class: Class 2 Laser
Max Output: Less than 1mW
Wave Length: 522～542 nm (green light)
Battery type: 2 AAA batteries
Battery life (Laser pointer): 20-hour maximum
Battery life (Presenter): 1050-hour maximum
Wireless operating distance: Approx 30m^1
Wireless technology: 2.4 GHz wireless technology
Support OS: Windows Vista, Windows 7, Windows 8
Interface: USB