This is a compact and inexpensive AA light and good as such. The light output is not as great as that of larger and more expensive AA lights, but this is largely made up in run time. The twist switch saves length but worked a bit rough until I repeatedly cleaned and lubricated the threads. It is slim as well as short and yet appears to be very strong. It did not suffer when I repeatedly dropped it on paved streets. I miss knurling, but the nut and bolt theme is attractive. I currently have it on my key chain but hope to replace it with a higher output light, perhaps CR123 powered.
I now have several lights with heads continuous with the body. This saves space and weight and increases strength, but I am not sure whether I will be able to remove the electrical parts for maintenance and modification. The obvious way is to press on the lens with a wooden dowel, but I have not tried that yet.
It works on 3.7 V 14500 cells with moderately more output, though that is not mentioned in the product description.