2004 Toyota Tundra Owners Manual - Page 313
2004 Toyota Tundra Manual
Page 313 highlights
'04 TUNDRA_U (L/O 0309) Type C cup holders are equipped with a detachable adapter for each holder. When you remove the adapter, a bigger cup can be held in the holder. Type D Type F Type E Type G 313 2004 TUNDRA from Sep. '03 Prod. (OM34426U)