Product review (5 stars): Simple And Reliable
This device is small ("face" is about the size of a silver dollar), light and easy to install (I hung it on a small 'finishing nail' or 'brad').  Additionally no batteries required!.  Classic design and contrast in dial face is easy to see & read in many lighting conditions.  It seems to be "nimble" in that the mechanism responds to changing weather conditions quickly and seems to be reliable.