The 2 most common types of outlets are:
Duplex:
Duplex outlets have two distinctive features:
- Two oval plugs
- Open screw hole in center (for attaching cover plate)
Block / GFCI:
Block outlets (often GFCI with the test/reset buttons in the center) are different from duplex receptacles:
- Rectangular in shape
- No center screw hole
You May Have Both
It's not uncommon for a home to have mixed outlets throughout - one room might have duplex outlets, while another room has block style receptacles. We've even seen homes where the two styles are present in a single room.
Save yourself the extra trip to the store (or extra shipping fees) - carefully assess each outlet you are purchasing new covers for. The easiest way to do this is to look for a center screw openings on the outlet itself.
More Outlet Types
The amperage (15A vs 20A) does not effect which type of cover your receptacle requires.
For outlets behind a TV or large piece of furniture, you can get outlets that come with cover plates and are recessed into the wall.
If you have round outlets or large amp ones (30A, 50A or 60A), you'll need another plate entirely.
For electrical outlets installed in floors, cover plates are not sold separately, so you'll need to replace the floor box unit entirely to get a new cover.