I want to start by saying this is not my first Sofirn light. I currently own several other models from this manufacturer and continue to explore the product line for buying opportunities. My experience with this company consistently delivers solid satisfaction. My experiences are what brought the unique SD05 to my attention. I am not a diver but I liked what I saw in regards to the control mechanism as well as the form factor of the unit. These two things along with my experience with the brand was enough to close the deal for me.Out of the box this light exhibits the quality I have come to expect from Sofirn. This particular package included a 21700 lithium battery with a 4000 mah rating. It also included a charger and cable for the charger. As you can see in my photos there are two additional o’rings as well as a very capable lanyard. The manual is straightforward and gives a great summary on how much time you can get from each power setting before your battery is exhausted. It also provides accurate distances for each setting. I was able to closely verify the distances shown in the manual. The high setting probably exceeds the manual’s rating of 270m but at this range it is hard to distinguish.This unit is different than many of the lights on the market today. It only has three power levels and it does not have a strobe feature. I was worried about the limited number of settings when I was researching this unit but I have actually developed a fondness for the lack of strobe. I find myself regularly wishing some of my other lights did not have the strobe option. This light eliminates all the button pushing that has to take place to get the other lights on the correct setting. I think the simplicity of this one will be very attractive to most buyers. I am not a diver but I do get into a lot of situations where water can be an issue. This unit has a dive rating of 100m so I won’t have to worry about dropping it into a water trough or into the river when I’m hunting frogs or gigging fish. The endurance of this light along with the water resistance is going to be great over the long haul. Based on my deep inspection of the build quality and the experiences I have had with Sofirn I think it will hold up well to the test of time.I also own multiple Sofirn SP36 units, multiple SC31s, SP32v2 and an older C8 variant that has been through so much. I recommend the SD05 to anyone that needs a solid torch with extreme waterproof/diving capabilities and a lot of lighting power. I think it will continue to increase its role in my light arsenal. The lumen level this puts out along with the uniqueness of its feature set has really stood out to me now that I have had a chance to use it for a while. Enjoy it like I have.