January 2015 the first ever winter Spartan race is taking place in Slovakia. There is a mandatory equipment rule - carry an emergency whistle. As a promotional material for mudrun.cz (OCR magazine) these whistles tied to 550 paracord will be given away as a promotional item or for those who forgot their whistle at home.
It's pretty straight forward print since I am noob myself. Print in hi-vis filament, attach a paracord or keyring. Whistle.