Advice on threaded brass adapter for kitchen tap

[saint7dave]

Hi, to cut a long story short, we rented a hot tub recently and the guy setting it up connected something like this to my kitchen tap to connect a hose and fill it with warm water:

Hot tub guy removed the black part from our kitchen tap:

And screwed the adapter into here, which has a 15mm diameter:

Can anyone point me in the right direction to find a similar one that would fit? I've looked but I'm not having much luck.

 

[SFK]

https://www.amazon.co.uk/Expandable-Stretch-Fittings-Adaptors-Connectors/dp/B073PC57XC
https://www.amazon.co.uk/Tesmotor-No-Leak-Connector-Fitting-Adapter（1/dp/B085PXDNWY

But I think they might be 3/4"

 

[oldbuffer]

Have a look at https://www.cromwell.co.uk/shop/han...MI6M6nyq308QIV1oTVCh1yVQkDEAQYBSABEgI4APD_BwE

 

[Nozzle]

https://www.toolstation.com/brass-internal-adaptor/p39197

Stay well away from Amazon, the tax dodging shysters