here is an image of a misc. meshwheel. they all look very similar, a flat disc with holes drilled. the holes allow the mesh to be attached and for water to reach the magnet of the impeller for cooling.
the mesh used is enkamat PF4 (it can be purchased from many online aquarium shops) fishing line or mini zip ties are used to attach the mesh.
this mod can be done to various pumps to increase the air input, however be sure to research it and use a killawatt. if the mesh rubs on the volute it will increase the electrical draw and melt down the pump, possibly causing a fire.
hth.