Many electrical outlets in Thailand look like standard U.S. outlets, with round grooves to the sides of the main prongs. These outlets, known as hybrid outlets, do not require an adapter to work with U.S. appliances.
Hybrid outlets also work with standard Thai appliances, which have two round prongs. Older-style Thai electrical outlets have only two small holes for round prongs. The older outlets require an adapter to work with U.S. appliances.
Adapters are available for purchase in Thailand for about 50 cents as of 2014. They are also available at stores such as Radio Shack and REI in the United States. The adapters are often labeled as working in Asia and continental Europe.