Type 22 radiators feature double panels and convector fins, yet do so with the same dimensions as single panel convector radiators do.
That said, they can deliver a higher heat output than their single panel counterparts, whilst maintaining the same diminutive profile that makes them an appealing option for tight spaces such as hallways or conservatories.
For a deeper insight, take a look at our article, About (Type 22) double panel convector radiators.