Yup, says it is 7.3mm in this dimensional specs pdf
http://downloads.dell.com/Manuals/all-products/esuprt_display_projector/esuprt_Display/dell-u2717d-monitor_Reference%20Guide_en-us.pdf
That rear view picture is wrong, they have the manual for the U2717D on the site and it doesn't look like that.
http://downloads.dell.com/Manuals/all-products/esuprt_display_projector/esuprt_Display/dell-u2717d-monitor_User%27s%20Guide_en-us.pdf