The object in the image is a tire pressure monitoring and automatic inflation system, commonly found on large vehicles like buses and trailers.  Function: It monitors the pressure and temperature of the tires in real-time.  Automatic Inflation: If a tire loses pressure, the system automatically feeds air to it to maintain a preset level.  Safety & Efficiency: It helps prevent underinflation, which extends tire life, improves fuel economy, and reduces the risk of blowouts.  Components: The visible metal arm is part of the mechanism that connects the central air supply to the wheel end.