Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good, but there is a catch

It works as advertised and very easy to carry and easy to use. But this is not a replacement for an actual lens cleaning kit. Just an easy to carry thing that can help you in the middle of a trip where you can't sit down and clean your lens with a cleaner.I went to a beach that was very windy and went very close to the water. The wind had fine sand particles and water with it and all of that stuck to my lens. I came back to my car and tried to clean the lens with this pen. When I used the brush it made it worse. It spread the water and sand all over the lens. Then I used the other end for quite a long time to clean the entire mess. Note that the more you use the liquid end the more you affect the lens coating and also the liquid is going to dry up gradually.