4 LIGHTING MODES: VICTGOAL bike taillight features a side button that allows adjustment of four different lighting modes to suit your preference. Modes include fast flashing, slow flashing, all lights flashing, and constant lighting. Multiple lighting options provide flexibility for various riding conditions. USB RECHARGEABLE: This rear bike light has a built-in 220 mAh rechargeable lithium battery. It can be charged using a USB cable from computers, chargers, or portable power banks. Fully charges in approximately 1.5 hours and provides 4 to 8 hours of runtime on a full charge. SIMPLE TO INSTALL: The taillight includes a silicone mount strap with four secure openings, allowing firm attachment to bicycle seat posts or handlebars. It can also be mounted on belts, backpacks, or bike helmets. Designed to fit most bicycles for reliable rear visibility. WATERPROOF & DURABLE: Constructed with high-quality ABS material and a transparent lampshade, this taillight offers strong durability and resistance to impact. With an IPX4 waterproof rating, it withstands exposure to rain and snow, making it suitable for various weather conditions. VERSATILE BIKE LIGHT: The rotatable base allows for horizontal or vertical mounting on your bicycle. This LED safety taillight enhances visibility and is ideal for nighttime cycling, walking, jogging, or running.