YKK zippers, which we currently use in all of our products, are an example of the total domination of the market by a single manufacturer. It is said that at the ISPO and Friedrichshafen trade fair, about 95% of the products are equipped with YKK zippers with very good reason: these are the most durable zippers we know. The best proof of this is the fact that in almost 25 years of our business we cannot recall any, literally any, case of complaints associated with a YKK zipper. Even with CUMULUS sleeping bags of twenty years old, which we see sometimes, have zips that still work without any problem. We can say, with absolute confidence, that in this category, we use the best raw material in the world.