15 amp gfci for garage outlets
Receptacles rated 15 amps can be used on 15 amp circuits.

They can also be used on 20 amp circuits as long as you have more than one receptacle (one duplex or two single receptacles) on the circuit.

If you have a single receptacle on a circuit it has to be rated for the circuit, e.g. a 20 amp circuit would require a 20 amp receptacle. A single receptacle in this case is not a standard duplex receptacle. If you have a device with a 20 amp cord then you would need one of these. Otherwise, everything else is just fine with 15 amp receptacles.

Good luck.