Smartwool's Men's Merino Sport 150 Brief takes all of the tech you love from their Merino boxer briefs—a lightweight feel, breathability, anti-stink Merino—and adds a looser fit. With a fully functional fly and a wide, Merino-lined elastic waistband, you'll experience maximum comfort all day long. No matter if you're hitting the trail for a three-day camping trip or trying new sports, their Men's Merino 150 Boxer brings you the performance and comfort you can expect from their ultra-soft, responsibly sourced Merino wool.