Philmac Gas Fittings. MDPE Water Pipe Fittings. One end will fit 25mm (3/4") Blue MDPE water pipe, the other will fit ANY pipe in the range 15mm - 21mm. So you can attach MDPE pipe to PVC, ABS, copper, lead, steel, Alkathene, galvanised iron, stainless steel etc. with just one fitting.
eBay