For hiking, cycling and everyday use, the Mens Glen Vest gives you practical wind protection with a zip on upgrade option. This allows you to zip it together with a compatible inner jacket. So you can create a warm and functional combination when a fleece jacket alone is not enough. The gilet's windproof Stormlock outer fabric and robust, moisture insensitive Microguard synthetic insulation keep you nice and warm, even when it's worn on its own. Throw it on over a functional top after your work out!