The On Men's Lightweight Active Shorts are an ultralight, versatile pair with a perforated back. These shorts are engineered solely to help you perform better. A rear pocket and key loop secure your essentials, even when running at top speed. Soft but strong, the technical four-way stretch polyamideand elastane blends used in the front and inner briefs are fast-drying and offer total freedom of movement. Perforated polyester to the rear keeps you cool and the elasticated waistband hugs gently for a stay-put fit. While you're working up a sweat, the Lightweight Shorts are working on getting rid of it. The On Men's Lightweight Active Shorts are fast-drying, super-light and stretchy, with a streamlined design featuring everything you want, and nothing you don't.