Press the nose against the workpiece pull the trigger and the shell will drive the fastener directly into the concrete.
How to fasten to concrete floor.
As you drive in the pin the sleeve expands outward.
Drill pilot holes through the bottom plate in the locations you are attaching it to the concrete making sure to penetrate the concrete slightly to mark the locations.
Drill pilot holes through the concrete using a drill bit the same size or slightly smaller than the nail diameter.
To use it load a special gun nail and a 22 caliber gun shell into the barrel.