$re = '/[^,]*LED[^,]*/m';
$str = 'Display: 27 in, VA, Viewing angles (H/V): 170 / 160, W-LED, 1920 x 1080 pixels
Display: 21.5 in, VA, Edge LED (Local Dimming), 1920 x 1080 pixels';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php