Measure the width of your fireplace opening. Divide the measurement by two. This is half the width of the fireplace. Use this measurement to find the center of your fireplace lintel and mark this location with a piece of chalk.
Drill a 1-inch pilot hole into the underside of the lintel, as far back as you can, using a masonry drill. This should be done in the location you marked with chalk.
Screw the center bracket to the pilot hole you drilled in the underside of the lintel.
Choose one of the rods and grip the looped end of the rod with vise grip pliers. Bend the looped end of the rod to a 90-degree angle. Insert the non-looped end of the rod into the left side of the center bracket, then place the flattened looped end of the rod against the edge of the fireplace opening. Drill a hole through the looped end of the rod where it attaches to the side of the fireplace opening.
Remove the rod from the bracket and string the mesh curtain through the rod. Return the rod to the center bracket, hold the looped end of the rod against the hole in the fireplace you made in Step 4, then screw the rod into place. Tighten the screw until the rod is secure.
Repeat Steps 4 and 5 with the leftover rod, this time attaching the rod to the right side of the fireplace instead of the left.