The Sterling 700, like its' big brother the 800 is a self-illuminating viewer using two 'D' type batteries. It has inter-occular adjustment (meaning that the distance between the eyepieces can be adjusted to aid focusing)as well as the ability to focus each eyepiece individually. It is an above average viewer - while not giving as well defined an image as the Realist Red-Dot. It caters for all stereo 35mm formats which inevitably means that the smaller formats lose out in the resulting size of the image to be viewed..
Makes a good second or third viewer when showing slides to a small group.