Brass Union DR 22mm Compression x 1/2" MI European Size Collector Connection
2mm is generally a European size but found in some solar hot water collectors sold in Australia. Early Apricus systems were one of the many brands the had 22mm copper from the collector. The 22mm compression fitting to 15mm male union is normally used to join the flow and return lines to the solar hot water collector.22mm x 15mm male compression joiner has a DR brass body with 22mm compression x 1/2" male thread. The joiner comes complete with brass or copper compression olive. The joiner is used to connect to flat plate solar panels or evacuated tube manifolds outlet/inlet.