It's a stabilizer that clamps around the bottom of a 1U device such as a network switch. Most applications will require you to print two per device for stability. 

Indentations on bottom and between uprights are for non-slip pads. I use 1.5mm thick non-slip silicone material that I found on amazon, cut into 20mm squares. An additional pad on one of the uprights will prevent the print from slipping off if device is picked up.  

I print these in PLA with triangle infill at 10% and two walls. Very flexible but tough.