A mysterious gift in the mail

Video Channel
Please help us to find bad videos. Broken or unappropriated video content?
Dale, a viewer from the UK, sent this package containing some 3D-printed items related to the RC hobby.
The name plaques were easy enough to figure out -- but what were those strange things with three holes in them?
Fpvracer.lt is not the owner of this text/video/image/photo content, the real source of content is Youtube.com and user declared in this page publication as Youtube.com user, if you have any question about video removal, what was shared by open community, please contact Youtube.com directly or report bad/not working video links directly to video owner on Youtube.com. Removed video from Youtube.com will also be removed from here.