Maintenance notes for microscopes from Leitz' "grey era" (170 mm tube length) Two examples of the Leitz "grey era" microscopes: Leitz Dialux microscope Leitz Orthoplan microscope Leitz Periplan GF 10x M Eyepiece Leitz Lamphouse 50 Condenser Holders for Leitz Microscopes with 170 mm tube length Leitz Lamphouses 100 and 100Z