This is an identification light/safety marker that can be attached to helmets, Velcro backpacks, and shoulder bags. There is a lighting malfunction. Symptom: When lit in the visible light position, it sometimes lights up in IR. If you turn it on in the IR position first and then switch to blue, it lights up relatively normally. The IR appears slightly red to the naked eye. Uses one CR123A or 16340 lithium rechargeable battery. The battery cap is a real type that can be tightened with a screw. - Vertical lever down (visible light) Position 0 = Off, ① = Blue constant light, ② = Blue constant light + white flashing - Vertical lever up (IR) Position 0 = Off, ① = IR flashing, ② = IR constant light *The IR light performance of smartphone cameras is not very good, so it appears dark. The Velcro on the main body has been applied after degreasing. I cut and applied the extra parts of the Velcro on the battery cap myself. There is no case or instruction manual. Test battery included (remaining charge unknown. Please let me know if you don't need it.) Please refrain from purchasing if you are nervous or concerned about details. No pets. Non-smoking. Shipped via Yu-Packet Plus. Shipping cost included: 520 yen.