This page is credited in full to Dave Cushman who created it. His voice is expressed in black colour text and any additions or comments in blue belong to myself. Credit: Dave Cushman’s website.
Kirchhain Mating Nuc,
Picture from Swienty
This type of polystyrene hive was originally crafted in wood and has inwardly sloping sides to reduce, or eliminate, the attachment of combs. The angle of the sides is 76