0A Outlets: Some electrical outlets have a "T" shaped slot on the neutral instead of just a vertical slot. These outlets are rated for 20A, and can receive special plugs (with a sideways neutral prong) for appliances which draw more than 15A. This prevents people from tripping their circuit breakers by plugging them into 15A outlets by mistake. While 15A outlets are generally fed by 14AWG wire, 20A outlets are generally fed from 12AWG wire. There are exceptions for long runs or high temperature environments, which need thicker wire. A standard plug can still fit into this outlet because the T shaped slot will accept both kinds of neutral prongs.