"The description says 'compression connection'. This could mean that it will work with a nut and olive as some do; it will not. The connection is straight 1/2-inch male BSP, so needs to be screwed into a female socket."
"The old valve in the radiator had a slight taper thread. I replaced it with this one and even with ptfe tape it had a slight leak. I noticed then that it had a parallel thread so the only way I could get a result was to refurbish the old one which in the end solved the problem. Quite a frustrating waste of time really as I had to leave the job and try to get a tapered one in Screwfix but with no luck."