Very useful when plugging in to 30 amp campground or RV outlets. This little adapter allows you to plug in a regular appliance to any NEMA TT-30, 30 amp, RV type outlet. These types of outlets are commonly found in RV parks and campgrounds. Not to be confused with dryer outlets that have a similar appearance, a TT-30 plug only delivers 120 volts. Note, product appearance may differ from that pictured due to continual improvements.