This is a tiny shaped cylinder to stick at the bottom of the rudder of a BAMF2 discuss-launch RC glider.
It protects the fragile tail in the event of a un-catched landing.
Printed in Aero PLA, it weighs a fraction of a gram.
In retrospect, I should have printed it in plain PLA, as I needed a tiny bit of ballast in the tail to balance the CG.