jim_in_sussex wrote:

hard luck! I tried 2 B&Qs (Warehouses) about 10 days ago for the same,
one was sold out, but there was a hanging slot for them & the other had
a box with just 1 in it. about a quid IIRC

must be a fast seller, but then I suppose you only try twisting the
valve on once without one....

BTW 3/4BSP it is & PTFE tape did the job.

Thanks for that Jim - I must've overlooked them given I live in what
seems to be the home of B&Q warehouses (Bristol) - we've got at least
four of them within 10 miles (and a couple of the smaller ones too).

Mathew