Hi Tom and welcome. This model has a Double Action Only trigger hammer-fired pistol, using a protected internal hammer. Cheers, stay safe and enjoy!

Double action only trigger.

Hi Tom, this pistol is double action only.
The Security-380 uses the Secure Action system developed by Ruger. The hammer is internal and shrouded as opposed to the more common striker-fired action. This makes for a simple double-action-only system — the hammer is prepped slightly as the slide is pulled back, which also makes it easier to pull.
Stay safe & have a great day!