07-29-2013, 07:39 PM
It looks like an air drier to me. The metal cage is a safety to catch any flying debris in the event the inner glass/plastic vessel fails. There should be a desicant to absorb water vapor in the inner vessel. Wilkerson uses a color coded desicant blue is good, going to clear for time to change it out. Neat like, colored coarse sand grains type of material. Grainger is a good source.