This tray attaches by means of three screws. Each of these is cushioned by a soft rubber grommet of sorts that keeps the tray elevated so that an installed hard drive has rubber to dampen any vibration the drive may produce. To ensure this cushioning is complete, Kingwin also put a few soft pieces of rubber on the sides of the interior (the white circles below and on the right.)
FULL STORY @ OVERCLOCKERCAFE (http://www.overclockercafe.com/Reviews/other_misc/Kingwin_KF-83/index.htm)
