Let me start by saying that I love this light. I have it mounted on a backscatter tray and am using it with a GoPro for video. The light is very bright, wide and there is absolutely no hot spot. It's also a great value at $120 and that includes the battery, charger and nicely made hand mount. Here's what you can really expect for run times as I didn't find the manufacturer claim of 3 hour 10 minute burn time to be accurate. With the included battery you can expect to get about two hour...s and fifteen minutes or so of full brightness or near full brightness before the brightness drops to about 1/2 and power and the light starts to flash every 30 seconds (low battery warning). I also purchased a Keeppower 5200mah 26650 battery. This battery will provide a solid 30 minutes of additional burn time over the stock battery. The most important thing for me is that the light will last a full dive even if I'm doing monster two hour shallow water dive. This light fulfills that requirement even if the claims are exaggerated. I would recommend cleaning the light and o-rings before first use. I found the o-rings to feel gritty. I removed the o-rings, and wiped everything down until my alcohol dampened tissue no longer turned black. I then re-lubed the o-rings and re-installed. I would also recommend re-lubing on a regular basis. The mfr recommends keeping the light on for the entire dive to reduce the chance of flooding. I have found it's not an issue to turn on and off. Just make sure your o-rings are properly maintained and that you don't twist too far.
High Output, High Reliability, and High Portability
Beam Angle: 120° Degrees Super Wide Floodlighting
No Blind Angle for Underwater Photography
Lamp: CREE XM-L2 (U2) LED
Lamp Lifespan: 50,000 Hours
Rotary Switch: Offers High Reliability Underwater
Burn Time: 3-Hours and 10-Muintes
Construction: Body: Aircraft-Grade Type III Military Hard-Anodized Aluminum Lens: Tough 0.16" (4mm) Thick Glass O-Ring Sealed
Circuit Board: High Efficiency Constant Current Circuit: Provides Constant Brightness Reverse Polarity Protection: Prevents Damage from Improper Battery Installation Over-Discharge Protection for Battery Low Voltage Warning Function
Impact Resistant Tested: Drop from 3.3' (1 meter)
Depth Rating: of 492' (150 meters)
Dimensions (L x Dia. x Head Dia.): 5.75" x 1.34" x 1.97" (146mm x 34mm x 50mm)
Weight: 9.24oz (262g)
Power: 26650 (4000mAh) Lithium Ion Battery (included)