Professional lens cleaning pen that has a retractable brush for removing dust particles on one end and on the other has a cleaning tip with self-replenishing cleaning compound.
First remove particles with the retractable brush; then wipe the lens surface using a smooth one direction motion the cleaning compound easily removes smudges, fingerprints etc. When finished replace the cap over the cleaning tip leaving the cap half-twisted (twisting the cap replenishes the pens cleaning tip).
This is hands down the best lens cleaning product I have come across. It gets the job done in no-time, without leaving any kind of smearing or residue, and just as quickly is thrown back into the camera bag. Anyone who owns a camera, binoculars, a scope, or any other small glass they wish to see clearly through should have at least one of these pens.