You know, when you are looking for spare parts it is REALLY useful to know what it is for which you are looking for spares: type, make and model.
It is likely you are looking for dishwasher spares, since that is where you are posting but as to the make and model, we are left to guess.
You CAN help yourself, if you like. Find the make/model and start with one of these to try and find the coupling [ not cuppling :-) ]
http://www.espares.co.uk/browse/at1083/dishwashers?&mkwid=sN3FMFQKu&pcrid=84864107581&kword=dishwasher%20spares&match=e&plid=&pdv=c&gclid=CLuNhID5t8kCFesBwwodRpsMQQ
or here:
http://www.buyspares.co.uk/dishwasher-spares/catalogue.pl?path=463858:496324&mkwid=svnnvM4Xz&pcrid=78965615069&kword=dishwasher%20spares&match=e&plid=&pdv=c&gclid=CLTc44D5t8kCFQefGwodYI0Pcw
or here
http://www.partmaster.co.uk/dishwasher-parts/catalogue.pl?path=67231
Help yourself., November 2015