Coir entrance mats use fibres taken from coconut husks. The husks are processed to form a dense mat surface. The fibres create a stiff brushing action. The fibre texture scrapes mud and debris from shoes. They are often used in doorways and porches. They perform well in covered external spaces. https://antislipmats21731.tinyblogging.com/what-are-coir-mats-83722482