Microtech Knives OTF Combat Troodon Double Action out the front opening automatic knife. Microtech authorized dealer. The Combat Troodon is a Dual Action Auto Fire and Auto Retract that is 9 inches overall open length, 5.2 inches closed with a 3.75 inch blade. It is 25% larger than their flagship, the Microtech Troodon. It brings the slendle handle, contoured shap, radical design elements, and a sophisticated internal mechanism which improves operational functionality and reliability to a larger scale. The Combat Troodon is designed for a broad spectrum of utility and close quarter combat applications.