The eyepiece attachment for photographic lenses is intended for use as an observation device with magnification from 5x to 111x. It can convert a Pentax Screwmount interchangable lens (M42 mount) into a handheld spotting scope. The result of attaching the Tourist FL to the 1000mm is a 111x scope; with a 500mm lens it's 55x; with the 300mm it's 33x.
This attachment will work with any M42 photographic lens.
