Each of the nest sections slide out of the plywood mounting board to allow for easy cleaning, or inspection of the nest contents by licensed surveyors. When in situ the nests are held securely in position with metal hooks. The nests themselves are constructed from a mix of wood and concrete providing protection from predators and extreme weather. In research, the white mounting board was found to be the best colour for attracting House Martins. Supplied with fastenings for easy installation.