Vrs rear pistons

Good evening everyone.

Ive decided that my rear calipers are needing a refresh as they are sticking.

Purchased a rebuild kit with all seals and pistons, Everything looks good except the pistons. 

The inside of the piston is a smooth bore and then goes down to a smaller diameter at bottom i was expecting to see some sort of central pole with threads that screws on to the handbrake adjuster screw in the caliper. Cant find pics of vrs ones online but every golf and tt or a3 ones i have seen have had a female thread part in there.

Can anyone help are these the correct pistons or is there a part that needs transfered from inside the stock pistons?

Id like to find out the deal before i remove the old ones.

Cheers for any advice