This depth adapter kit lets you extend or reduce the mounting depth of two rack units 2u in your server rack by up to four inches if you39re using the adapter kit in a two post installation the extenders can support a total weight load of 20 lbs 9 kg if you39re using the adapter kit in a four post installation the extenders can support a total weight load of 130 lbs 59 kg you can even use two sets of extender brackets in a four post installati