We are currently unable to send out out-of-warranty, replacement hardware. That said, you can order replacement rack ears by visiting the link below.
3U Rack Ears
https://www.reliablehardware.com/pairrackrailsfullholepre-cut3space525incheslong.aspx
Rack Ear Specs
· 1/8'' Thick Steel (11 ga.)
· 1.55'' x .68'' x 5.25'' Long
· Tapped with 10-32 Threads
· Black Powder Coat Finish