Spur keychain 1:1.75
I created this spur as a keychain. The scale is a little larger than 1/2. Its size may be better suited clipped to a backpack...
Print either the small or large spur and then press fit the pin and button into place. (see picture) These were designed as a tight fit for my printer and Slic3R - adjustment may be needed.
The Sketchup file is included.