This is a simple camera that comes without a lens, but has a tiny aperture or 'pinhole'.
It comprises of a wooden box with a pinhole aperture at one end and a ground glass screen at the other end.
pght from a scene passes through the aperture and projects an inverted image on the opposite side of the box.
Students can view this image through a hole in the other end and can also change the image size by changing the box length.