A protective case system for a tablet computing device is described herein. The system includes an elongated outer conduit assembly within the interior of which is arranged an elongated cable member, the elongated outer conduit assembly being equipped with an inflatable sealing section adapted for engaging the interior of entry hole to seal and affix the outer conduit assembly. 9 mole percent and the monomer A unit amounts to 0. A gripper above the surface is displaceable between an upstream and downstream positions of the surface. The rate of upward flow of air in the chamber, the rate of rotation of the chains and the size of particles separated by the trommel are all adjusted in order to ensure that the particles that collect on the floor of the chamber are rich in precious metals and heavy minerals.