Product Review (submitted on June 10, 2011):
I've got 20 sets for my students. Taking them outside is a real eye opening experience for my students. Lots of interesting subjects to study; my favorite is dirt (nature's microscopic junkyard). The bulbs seem to have the half-life of a mayonnaise sandwich...buy some extras. Be careful with the focus knob...overturning can make the lense jam. Hold the subject against the clear viewer...not like the advertized picture.