The Men's Fast Wing Twinskin Shorts have a light, breathable liner, & a superlight outer shell with convenient pockets for gels, as well as a secure zipped pocket, along the back waist. Ideally suited to long trail runs in warm weather. Stretch breathable liner eliminates chaffing & enables free leg movement. Both the liner & the shell are very light & breathable. Gel pockets & a zipped pocket make it easy to carry a car key or credit card during daily runs.