The Cassettes are designed to easy fit the cassette house on the pump. The cassettes snaps into place with a click sound and are easily removed by unlatching the cassette with the lever. The Double Pump cassettes have some other unique features: The patented algorithm which calculates the true IAP (Intra Articular Pressure). The Cassettes are packaged in trays instead of pouches, which both prevents from dropping on the floor, but also makes them easier to keep sterile. Behind the Double Pump Patient Cassette, the SmartVision® optical sensor is located. With this sensor the Double Pump can automatically adjust pressure and flow when blood or debris is detected.