This is a magnetic switch type diving light (underwater light). You can adjust the light output by sliding it, and it's quite bright at the maximum setting. I stored it unused after purchase. When listing it, I submerged it in water as shown in image 6 and turned it on for about 2 hours, and there were no problems. There are only minor scratches from storage, and no noticeable damage. The batteries used are 18650 x 2. As a bonus, I will include two used 18650 lithium-ion batteries, a charger, and two zoom-type LED lights (image 1).