Lens Diameter = 42 mm. Brass base Diameter = 68 mm. The item "Microscope Bullseye Condenser Lens Lacquered Brass C1860" is in sale since Thursday, January 23, 2020.This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "houseofvega" and is located in Newcastle Under Lyme, Staffordshire. This item can be shipped to North, South, or Latin America, all countries in continental Asia, European Union member countries, Australia.