<page_title> IMac (Intel-based) </page_title> <section_title> Specifications of Unibody iMacs from 2009 through 2012 </section_title> <table> <cell> October 20, 2009 <row_header> Release date </row_header> </cell> <cell> 21.5 in (550 mm), 1920 × 1080 <row_header> Display </row_header> </cell> <cell> 27 in (690 mm), 2560 × 1440 <row_header> Display </row_header> </cell> <cell> Glossy glass-covered widescreen 16:9, LED backlighting and IPS technology <col_header> Component / processor model </col_header> <col_header> Model </col_header> <col_header> Release date </col_header> <col_header> Marketing model no. </col_header> <col_header> Model number </col_header> <col_header> Model identifier </col_header> <col_header> EMC no. </col_header> <col_header> Enclosure </col_header> <col_header> Display </col_header> </cell> </table>
In October 2009, a 16:9 aspect ratio screen was introduced in 21.5" and 27" IMac models.