The Fang 4 features a Full Containment System (FCS) with a hook-style jaw that allows the archer to push the FCS slide forward to lock the release on the D-loop, for use in a hands free hunting situation or pull the FCS slide back for repetitive shooting. The Fang 4 provides the ability to shoot with no sensitivity spring for the lightest possible setting or a medium and heavy spring, included in the package for heavier sensitivity settings. An independent trigger travel adjustment screw allows numerous different settings as desired by the archer. Adjustable thumb barrel positions can be attained with the large knurled thumb peg and teardrop. Pull the trigger to fire, then pull trigger again after firing to reset the hook.