12.7 mm Stainless Compression Fitting to 1/2 inch BSP Male
These compression fittings are the most common type to be used with immersion chillers on the market today. We highly recommend using these fittings on any and all immersion / ice bucket chillers to optimize the ability to quicky disconnect the liquid hosing for storage and ease of cleaning.
The industry standard fittings are Camlocks which can be found here. Alternatively this fitting can be used in conjunction with this brass Hozelock type fitting 

See here for instructions on how to use these fittings