From Thread Theory:
These form-fitting trunks are designed with comfort in mind. No center back seam, a reinforced inseam gusset and a shaped front cup make these boxers fit like a second skin without the worry of rubbing or shifting.
Short, athletic legs and a smooth elastic waistband create a streamlined silhouette that can be worn under everything from slim fit pants to gym shorts.
This pattern, as part of the Alpine Outdoors Collection, is a hard-wearing design with a classic fit. Create a hand-made wardrobe of these designs so as to always be comfortably and stylishly ready for the next adventure!
Recommended Fabrics: The knit you choose should have 60-75% stretch. Use a cotton, bamboo, or blended lightweight knit with (preferably) at least 4% spandex/elastane and 4-way stretch. The spandex/elastane content will assist trunks in retaining their shape. Avoid tissue weight knits as these will not be strong enough for trunks.
Sizes: to fit waists 24"-45"