The installation of the batteries is extremely difficult. It requires four AA batteries that are not provided and must be included in the final cost. Furthermore, the use of the product becomes even more challenging because it comes in a brown cardboard box without any indications on the outside and without a manual. To install the batteries, a screwdriver is definitely needed to open the compartment. They fit very tightly in their place, and it took me a while to figure out how to do it without dismantling the entire device, which was obviously unnecessary. The light intensity is extremely strong, so much so that it can even be used as an orange flashlight, but it only has two modes of operation: flash and continuous. I would like a frequency adjustment for the flashes. With such intensity, I am concerned about the battery life, and I really didn't want to go through the process of changing them again for the reasons I described above. However, it seems to have a satisfactory level of water resistance and relatively good construction quality. The two magnets on the back are very strong. Overall, I consider it a decent purchase that will sufficiently cover the lack of signaling if you "get stuck" at night on the road without lights in your car. However, it is not suitable for "impatient" users when it comes to changing batteries.