A photo of three NEMA 1–15P electric plugs. The middle plug is newer than the leftmost plug and has a wider face near the prongs. This design may reduce the risk of electric shock. The rightmost plug is for a model railroad power pack and has a noticeably wide face; electrically-operated toys sold in the US are subject to regulations that include a minimum size for the plug face (US 16 CFR §§ 1505.5(e)(3).)