In the video, a man is seen working on a bicycle. He is wearing blue gloves and is holding a syringe filled with a red liquid. The man is carefully injecting the liquid into the bicycle's brake system. The background is filled with various tools and equipment, indicating that the man is in a workshop or garage. The man's actions are deliberate and precise, suggesting that he is experienced in this task. The red liquid in the syringe appears to be a type of lubricant or hydraulic fluid, which is commonly used in bicycle brake systems to ensure smooth and efficient operation. The man's focus and attention to detail suggest that he is taking care to ensure that the brake system is functioning properly. Overall, the video provides a glimpse into the maintenance and repair of bicycle brake systems.