Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument, like astronomical telescopes, produces upside-down images. An advantage of this spyglass is the great stability of the image, which is not always obtainable with small conventional instruments. Moreover, thanks to its simplicity, it can be useful in teaching the basic principles of optics and the operation of more complex telescopes. (Contains 4 figures and 1 table.)