From Free Pascal wiki

TToolButton is a component that is used within TToolBar.

A TToolButton - a TGraphicControl descendant - has a lot of usual properties like Action, Caption, PopupMenu, ImageList etc. A DropdownMenu is available to react on a click. The button's Style property determines what the button looks like: tbsButton, tbsDropdown, tbsCheck, tbsDivider, or tbsSeparator.

See also