Aircraft

A320-200(THAI SMILE)
  Royal First Class Royal Silk Class Economy Class
Number of Seats - 42 263
Configuration - 2-2-2 31 - 65: 3-4-3
66 - 71: 2-3-2
Rows - 11-24 31-59
Over wing Rows - - 40-46
  Royal First Class Royal Silk Class Economy Class
Number of Seats - - 174
Configuration - - 3-3
Rows - - 31-59
Over wing Rows - - 40-46
  Royal First Class Royal Silk Class Economy Class
Number of Seats - 36 263
Configuration - 2-2-2 31 - 59: 2-4-2
60 - 64: 2-3-2
Rows - 11 - 17 31-64
Over wing Rows - - 34-47
  Royal First Class Royal Silk Class Economy Class
Number of Seats - - 168
Configuration - - 3-3
Rows - - 31-58
Over wing Rows - - 40-46
Economy Class Seat

As the airline cares about convenience throughout the flights, the seats are super wide to provide passengers convenience, quick and polite services.
Read More

My personal THAI experience