Handy, and works great - Nikon Lens Pen Cleaning Pen System

These work really well. Far better than trying use your shirt. They tend to lose their effectiveness after some use, especially when used to clean up oily smudges. Around my home, I still use the Lens Pen brush to clean out any debris off the lens, and then use a Zeiss glass cleaning wipe that are readily available in many locations. I save the Lens Pen cleaning pad, which does work really well, for use in the field. The only other brand of Lens Pen I have tried is Leupold. There isn't much difference that I can detect between the two.
Pros: portable way to quickly clean on the go
Cons: none

This review was written in the old system and had content requirements that are different than reviews written today.