Identification marker light, tacticals light with three modes of: alway on, flashing turn off Attention, when the battery is exhausted, you can replace the battery ( but changing the battery will affect the waterproof function of the product , helmet flashing light be made from good which with good sealing ( waterproof) and flexibility Powerful function, this tacticals light is an essential item for your outdoor activities, such as cycling, hiking,, diving you can stick it on your tacticals helmet, hangs it on it on your backpack, stick on your bicycles seats or hangs on your neck Wonderful gift, sweet warm friend family or yourself