Helotex VG1 CREE LED Adjustable Focus AA Zoom Flashlight

What is the diameter of the helotex vg1? will this fit in a 1" (1-inch) rail mount on my gun? is it sturdy enough handle recoil from shotgun?

Can this light use a 3.7v, 14500 Li-Ion battery?

battery life? Obviously types of batteries will vary, but thinking of mounting to my bike and using for 1-2 hours straight?

can this fit in the condor pistol mag pouch