This antique Bausch & Lomb lens is a must-have for any collector of scientific instruments. With its original design and craftsmanship, it is a true representation of the time period it was manufactured in, which was pre-1930. The lens is perfect for display purposes or for use in a laboratory setting. It has a unique 31-26-19 measurement that sets it apart from other lenses of its time. Don't miss out on the opportunity to own a piece of history with this original Bausch & Lomb lens.