Fenix SD11 Dive Torch
Fenix SD11 Dive torch, takes one Lithium 18650 battery, or two Lithium CR123 batteries. Depth rated to 100 metres, and with a maximum output of 1000 lumens.
It has two LEDs, one red and one white. The brightness / duration levels are: 250 lumens for 3 hours on the red/white setting; 500 lumens for 3.7 hours on the white LED; and 1000 lumens for 2 hours on the top setting. The red LED also functions as a battery level indicator.
The SD11 is made of alloy, is durable, and has a double O ring seal. It is operated by a twist-bezel in the headset which is pretty easy to use in-water and with gloves on. It has a regulated output and polarity protection.
Weight is 133g without the battery, the torch is c.14cm long and c.3.5cm at its widest; so it really should not be very noticeable to wear a pair on the helmet. It uses a Cree XM - L2 U2 (white) and XQ - E (red) LEDs for those to whom this detail means something!