The Compact Rail Green Laser has a 3 point touch system. It will allow you to turn it on by touching the pressure points which are located on both sides of the laser housing. Press it again and it will go into the strobe mode.  Pressing again will turn it off.
Length: 1.46 inches                             
Finish: matte black
Height: 1.2 inches                       
Weight: 1.4 ounces
Voltage: 3 OV                                   
Battery: 1 CR2
Battery life: 3 hours continuous                                                
Laser: 5 mill watt green