I love these undervests. Wondered when I received them whether I should have gone with a medium rather than a small, as they are very tight fitting. But upon using them, I absolutely love them - I barely notice I am wearing them, they are so comfy and lightweight. I would have liked it if there was an option to get a black and grey one in one pack as I prefer darker colours for mountain biking - I expect the white won't be white for very long. But it won't matter much as I use these under a thin long-sleeve top for all-day bike touring/adventuring. They also weigh nothing in my overnight saddle bag. So perfect - thanks so much!