Push Fit Plumbing 15mm Coupler Whitespeed ( always use lubricant & pipe inserts/stiffeners ) BS EN ISO 9002 & Conforms To BS7291 part 1 & 2. For Hot & Cold & Central Heating Systems So These PB Fittings Will Not Be Affected By Anti Corrosion Properties ie Sentinal & Furnox. Can Also Be Used on Copper When Adapting To Central Heating Systems . Use The Demountable Tool To Remove The Pipe From The Fitting . NO NEED TO CHANGE THE GRAB RING EITHER. ( fully demountable )