Alde rubber vertical elbow connector with air bleed valve. Alde rubber connectors are made from 21.4 mm EPDM rubber, tested and used in central heating systems for over a decade. Compatible with the 22 mm aluminium heating circuit, tube can be fitted to the rubber by hand. Always ensure there is at least 3 cm of tube inside the rubber connector, and a fitted spring clip, for the heating circuit to be watertight. Part Number 1900-245