Guangzhou Yuadon Electric Co., Ltd. is also a 30 amp plug manufacturer. It is a plug with three prongs and has 120 bolts with a 30 amp breaker. They are specifically designed for trailers. These plugs are available at Yuadon's website. Usually, people assume that it has can be wired with 240 volts because of the way they are designed. They are very easy to use. Just track the color coding in order to connect. Use the right size of the wire.