Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Nearly useless

The pen is supposedly designed to reach the corners as well as the surfaces of the imaging sensor on digital SLR cameras. It may work just fine on some model cameras with smaller sensors (or larger sensor cavities), but on a Canon 5D it is worthless. The circumference of the pen itself is too large. In order to get close to the corners with the cleaning tip you have to tilt the pen at an extreme angle. This angle causes the flat cleaning surface to not make contact with the sensor. Since the shipping and handling was a large percentage of the total cost, and the item was not very expensive, it's not even worth it to me to deal with sending it back or trying to get a refund. It did seems to work on the parts of the sensor the tip could reach, but the poor shaft design and the inability of the tip to reach the corners makes it a useless item for me.