It's a beefy long led bumper for the ZMR250 quadcopter frame.
With a matching short bumper for the front.
The long bumper fits 3 segments of 5050 LED strip with a slight overhang.
1 - Print it
2 - hot glue on the led strip
3 - screw it onto your frame with some m3 screws
4 - go fly
5 - find a good tree to crash into
6 - repeat from step 4