These images illustrate the stage and arm of the Grunow 'No. 5' or First Class Microscope. The arm was designed to swing out to allow easier access to the stage and also facilitate changing objectives. The stage includes two sliding slide-holders, each attached via a single screw to a dovetailed piece fitting into the stage; this allowed them to adjust not only for position and size of the specimen, but also, at least to some degree, unusually-shaped slides. The entire stage assembly can also rotate, an innovation invented by Joseph Zentmayer. In this case, if rotated all the way to the other side, the lever control would be suitable for a left-handed user.