Mines an Armster armrest. I'm not sure if there are any other makes about tbh. The armster one is very good, and very well made, although its not built to take a lot of weight, so dont lean on it... It is just an armrest.
It does have a storage compartment, and the pad section slides forward.
The whole thing lifts up out of the way, and fits between the seats in an upright position. It fastens to the centre console with 4 screws, and only takes a very short time to fit.
They are not cheap, but they do what it says on the tin