32mm magnetic filter holder for vintage Bausch & Lomb microscope. Great for dark field and color filters. This is a secondary holder so 2 or more filters can be utilized at the same time. Magnet is .375 X .20 inch 9.54mm X 5mm. Magnetically attaches to the iris screw head. Made in Tinkercad https://www.tinkercad.com/things/7u5YDDnRaFb