<https://kalischacero.com/en/products/purlins/>
<http://schema.org/description>
"Purlins have a vast variety of uses in building and roofing structures. C Purlin: Open «C» shaped purlins fabricated with galvanized structural steels for longer lifespan, they are used for framing wall openings, support pillars, crossbars, and other structural elements."
<https://kalischacero.com/en/products/purlins/>