Men's Muck Boots Muckmaster Tall Work Boots The original Muckmaster, serving farmers and outdoor workers for over a decade, now comes with a gusset construction for an extended fit. Delivering the same high performance and protection as the original, the Muckmaster XF offers up to 5 more inches of accommodation for optimal fit and comfort. This rugged boot withstands sharp objects while the breathable lining keeps your feet cool and dry in challenging weather conditions.