These are rack mount brackets for the Cisco Business (CBS) 250/350 and Catalyst 1200, 8 and 16 port switches to allow for flush mounting in a network rack. The brackets that come with these switches causes the devices to stick out about an inch from other devices. This is both unsightly and annoying to route cables around. These flush mount brackets move the device back inline with other networking equipment in a rack.

These rack ears can support the weight of the device, I printed mine in PETG with some additional edge loops for added support. Theoretically you could print these with 100% infill for additional support. However, the weakest part of the print will be the tab that goes into the switch, since Cisco chose this method of mounting, rather than additional screws. Try to avoid any kind of rotation on the device. For best results, let this switch rest on another device. 

I've uploaded the original Fusion 360 model so if anyone wants to make changes, please feel free.