A chitosan enhanced dewatering bag reduces the amount of silt, sedimentation and suspended solids from incoming water. A high frequency reference signal and a low frequency reference signal can be written onto the magnetic media. Each inner path selector includes a hollow rotating shaft rotatably mounted between the upper and lower rotating plates, a path select tubing connected to the rotating shaft to rotate along with the rotating shaft, and a disc mounted to a lower end of the rotating shaft, and provided with a plurality of circumferentially-arranged paths. The strips extend across the open area of the window frame and are spaced from each other at a distance that prevents the pet from exiting the vehicle.