What is the difference between the MTT office and the Chaengwattana office for extending a TR visa in Thailand?

The user inquired about the difference between the MTT office and the Chaengwattana office regarding the extension of a 30-day Tourist Visa (TR). Community members clarified that for a 60-day tourist visa, one should go to the Chaengwattana office, not the MTT office. They also provided a list of required documents for the visa extension, including a passport, copies of specific passport pages, a TM6 form with an arrival stamp, a fee of 1900 baht, and a passport photo. Additionally, it was noted that there is a printing service available on the first floor if needed.