Integrated trigger safeties
These safeties, similar to grip safeties, are de-activated as a natural consequence of the shooter firing the firearm, but are engaged in most other circumstances. The trigger is composed of two interdependent parts, and the shooter in firing the firearm manipulates both parts of the trigger. Conversely, unintentional pressure or a strike against the trigger is unlikely to do so, and such an action will not fire the firearm. Such a design, made popular by Glock pistols, incorporates a trigger with a spring-loaded lever in its lower half. This lever which protrudes from the trigger face must be fully depressed in order to disengage a lock that allows the main trigger body to move. Unintentional pressure against the top of the trigger without pressing the lever does not disengage the lock and the trigger will not move. Other designs include a spring-loaded pad that forms the upper portion of the trigger face and manipulates a similar lock. This design has more moving parts, but is advantageous in that accidental pressure on the lock release has reduced leverage thus requiring more force to pull the main trigger, where force against the lower portion does not release the lock and will not move the trigger.