When you enter on a non imm o visa, that is valid to stay in Thailand for 90 days
@Mi**
, then after 60 days you can ask for this extension (1,900฿). If you have an Non imm OA visa you can stay for a year and go out and in the country as many times as you want. 90 days report still needed ! Every time you enter Thailand, you get another year. So if you leave and come back just before y'r visa expires (the sticker), you get a full year. Watch out, this extra year is NOT multi entry. To keep that year alive (also regular year extensions), you can buy a single or multi re-entry permit