The expandable, plastic, mesh bag, is used to hold a small pack of silica-gel (desiccant) in a copper conductor, Openable Joint. The 6mm square mesh bag expands and neatly houses the pack of silica-gel. The silica-gel is intended to absorb any moisture or condensation that may enter or occur in the Openable Joint; thereby ensuring that the copper conductors remain dry and serviceable for a long time. The bag is nominally 12mm wide x 600mm long, but is expandable up to some Ø220mm dia if required. The 6mm mesh is made up of small plastic strands. One end of the bag is welded closed. A standard mesh bag has enough tensile strength to firmly hold a pack of silica –gel desiccant. Note: Each time the Openable Joint is re-entered, replace the bag of silica-gel with a new one.