The buttery soft, always flattering Foundation 365 Tank from Prana looks great worn solo or underneath season after season. The sleeveless tank top has a round neckline, racerback back and seam detailing at the center back. And this tank lives up to its name. The Tencel modal with a little elastane has enough stretch to be worn for all your activities, but is so soft and snug that you might be tempted to wear it at night too. Don't worry, we won't tell anyone.