This t-shirt is made from a mixture of two fibers:
80% merino wool and 20% nylon - the addition of synthetic fiber improves the mechanical resistance of the merino fiber without affecting its properties.
Merinowool clothes do not have a rival in comfort and versatility and can be used in various activities: running, mountain climbing, skiing, cycling, travel or a relaxed walk in the park. Because they do not develop unpleasant odors, they can be worn for a long time without any worry.
And if you want to integrate it back into nature: burying it will completely degrade itself in 6-9 months where synthetics require even 30-40 years (!).