JP.GunCAD on Twitter: "Introducing Mack, the Knife. A fully DIY, OTF, double acting automatic knife. Live now for download. Mackie's back in town! Enjoy! https://t.co/SnU8jIPNBl" / Twitter
OTF Knife Switch Blade (Functional) "improved" version v1.3 by mathiaspl20 | Download free STL model | Printables.com