Product Composition Disposable Negative Pressure Drainage System consists of negative pressure ball, interface, screw cap, one-way valve, air inlet tube, Robert clamp, auxiliary belt, fixed clamp, drainage tube, and puncture needle. Drainage tubes are divided into round drainage tubes and flat drainage tubes according to their shape and structure. The flat drainage tube is composed of a round tube and a flat tube through a triangular joint. Intended Use: For superficial general wound drainage in clinical operations.