This supportive insole adds cushioning and freshens up your boots, with an innovative probiotic technology that controls odor naturally. Men's sizes: Small = 6.5-8, Medium = 8.5-10, Large = 10.5-12, X-Large = 12.5-14. KEEN Utility believes in creating work boots that make work and life better. In effort to further support that mission, KEEN Utility has been “Putting Good to Work” through its non-profit partnerships within the Project Build program. From helping put veterans back on their feet to supporting conversation corps work across the country to creating work footwear consciously, KEEN Utility puts good to work.