Objective, 1/2 inch, in cannister, having correction collar and cover slip adjustment Objective, 1/2 inch
Objective, holoscopic, 12mm. in cannister, W. Watson & Sons Limited, 313 High Holborn, London, England. Objective, holoscopic, 12mm. in cannister
Objective, 8mm, holoscopic, in cannister, by W. Watson and Sons Ltd., 313 High Holborn, London, England. Objective, 8mm
