lock shield

[wanttolearn]

Hi guys I'm new to plumbing but just moved a radiator in a bathroom as it was already taken down by a separate plumber. Fitted rad but can't no heat to it blead all rads and tried turning all trv off to force the air out but still nothing.
There a danfoss trv and lock shield either side but I haven't seen this type of lockshield before.
So not sure how or if it's on. I took the cap off it and looks like you can fit a allan key inside to turn but not sure
Any info

 

[Atouchofgas]

Take cap off and get a 6mm Allen key to open it back up

 

[wanttolearn]

Thanks alot really was not sure