Led monitor series dell ultrasharp screen size 25 inches max resolution 2 560 x 1 440 pixel lcd technology ips response time 8 ms aspect ratio 169 contrast ratio dynamic 2 000 0001 contrast ratio typical 1 0001 brightness 350 cdm refresh rate 60 hz widescreen dot pitch 0 216 mm viewing angle 178178 pixel density 11749 ppi hdcp enabled horizontal frequency range 30 113 khz vertical frequency range 56 86 hz number of hdmi inputs