These are a buzzer mount and a general protector which I use to mount my receiver on for a 155mm quadcopter frame. The frame in question is a cheap frame that goes biy the name of QAV-X4 on Aliexpress.
Both mount slide over standard 5mm standoffs and are 20mm in height. Width between both standoffs is 18mm. If you want to customize the width between the standoffs it can easily been done by modifying the included OpenSCAD files.
I print these items in flexible filament such as Ninjaflex for ruggedness.
Use flexible filament for added ruggedness.