What kind of connection is this?

[u/busybody87]

Hello all, not technically DIY but there is so much knowledge on this sub I'm hoping someone can help. I've bought a house and all the radiators are like the picture, they have one pipe coming out of the floor then another on the end that looks like it returns behind it. I've only ever had radiators that have both pipes coming out of the floor and I don't know if this is a different type of system and if it is will it need to be replaced? The heating runs from a combination boiler if that helps?

[u/Brocklette]

The system "should" be the same as all other pipe lay outs for a hot water heating system.