1. Which side of the door are you installing the closer on?
The outswing / push side of the door?
Or the inswing / pull side of the door.
2. When looking at the door where the closer is going to be installed on the outswing / push side.
Hinges on the right is a right hand door.
Hinges on the left is a left hand door.
3. When looking at the door where the closer is going to be installed on the inswing / pull side.
Hinges on the right is a left hand door.
Hinges on the left is a right hand door.