Heat Absorbing Glass for Beseler 23C Condenser Enlargers

This is the heat absorbing glass specifically sized for Beseler 23C condenser enlargers. It is simply inserted into the top slot in the lamphouse filter drawer to eliminate much of the infrared radiation from the light produced by the enlarging lamp, thus helping to protect the negative and any filters from heat damage and minimizing negative "popping" which affects focus. The glass fits all versions of the 23C condenser enlarger with filter drawer.