This depth adapter kit lets you extend or reduce the mounting depth of one rack unit 1u 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 10 lbs 45 kg if you39re using the adapter kit in a four post installation the extenders can support a total weight load of 90 lbs 40 kg you can even use two sets of extender brackets in a four post installation an