How does the framing nailer work with a black button grey button

Dewalt has two triggers available for their framing nailer. The black trigger (390746-00) is a bump style trigger. While holding the trigger, you will be able to fire a nail by pressing nose against work. This trigger is preferred by most framers because it is much faster. Gray trigger will only allow one nail to be fired. Bumping will not work with the gray trigger. With trigger released, you must place the nose against work then pull trigger to fire. To fire next round, you must release trigger, pull gun off the work, again place nose against work then press trigger. Check dewalt web site for recall information. Some dewalt framers have been recalled for faulty trigger. Good luck with your projects.