This is shredded particles of tree fern. It consists of fluffy bits and small twigs - most under 2". This new style of tree fern fiber is quite long-lasting and is used by itself. It distributes water evenly throughout the pot and among the root system of your orchid. Phals love it, along with cymbidiums, encyclias and oncidiums. Surely other types of orchids will thrive in this media also.
This is NOT the traditional tree fern product historically used in the orchid industry - this is a new media sustainably harvested in New Zealand and was featured in an article in the October 2020 AOS Orchids magazine.