How do I tighten this...?

[Peter B]

the right in the first picture is the lockshield and on the left is the extension piece that goes into the manifold. The extension piece has no flats on its side with which to grip it, only two little stubby bits inside the fitting, which you can see in the second picture.

How do I tighten the extension piece into the manifold, so that I can then screw the lockshield into it? I'm guessing I need some special plumber's tool...

[A Plumber]

Go to your nearest plumbing merchants, and there is a special tool to do the job.

[newshound]

A suitable allen key may do it, or even a big screwdriver. The plumbers' special is basically an allen key with a couple of mods.

[The Medway Handyman]

'ere tiz

[Peter B]

that's a bit on the titchy side. Should've mentionrd, but it didn't seem pertinent at the time, but the extension piece is 1" BSP - which would make buying something that big for a one-off job ridiculously expensive, I guess.

[John Rumm]

I suspect the large allen key affair designed for fitting tails into rads will do the trick - they usually have a couple of notches in the end which will probably fit the lugs.

[Peter B]

Made my own in the end :)

[John Rumm]