Imperial 1/4" O/D to 6mm O/D metric adaptor. Allows the use of Pollywog nozzles and other components on foreign systems that run 1/4" pipework. Please note that these 2 sizes of pipework are very similar in size, the 1/4" pipework pushes into the grey part of the adaptor and 6mm pipework pushes into the black part of the adaptor.