The ROCKBROS A8Pro is a multifunctional safety system for bicycles that combines a tail light, an electronic horn, and an anti-theft alarm into one compact device. It features a high-brightness COB LED chip with four lighting modes, including steady and flashing options at high, medium, and low brightness. To make your ride easier, a built-in light sensor handles automatic on/off switching, while a brake sensor automatically increases the light's brightness when you slow down. Constructed from a durable PC and ABS housing, the unit is IPX5 water-resistant and weighs approximately 48 g. It is powered by a 700 mAh rechargeable lithium battery via a USB-C port. For security, the device includes a vibration sensor that triggers a 115 dB horn when movement is detected, which you can manage using the included wireless remote from a distance of 10 to 80 meters. This system fits securely on round seat-posts or saddle rails with 50-55 mm spacing. The package comes with everything needed for installation, including a variety of screws, zip-ties, and silicone pads to ensure a stable fit. It is a practical choice for city cyclists who want integrated lighting and security without adding bulk to their bike.