STYLISH DESIGN WITH ADVANCED FABRIC: 88% Polyester, 12% Spandex. The Primer Pant is made from a four-way stretch polyester-spandex blend that provides a comfortable next-to-skin feel. Flat-lock seams, moisture-wicking mesh liner, and side-stretch panels conform to your body and allow for maximum body movement. Designed in the USA HEATING TECHNOLOGY: Tri-Zone Heat Elements. The 7.4-volt system has three heating elements, one on lower back and two on the thighs, that add heat to critical areas that keep your legs warm. LONG-LASTING WARMTH: 10 hours of heat. Temperature control: First, the built-in touch control button. With the simple push of our control button, you can choose from 4 heat settings indicated by colored LED or use our MW Connect App ADVANCED FABRIC TECHNOLOGY: The Primer Pant is made from a four-way stretch anti-odor polyester-spandex blend that provides a comfortable next-to-skin feel. Flat-lock seams, moisture-wicking mesh liner, and side-stretch panels conform to your body and allow for maximum body movement. LONG WARMING WITH BLUETOOTH-ENABLED APP: Heat in seconds with 7.4v 2200mAh Lithium-Ion Battery; The USB port for charging smartphones or other mobile devices; Incorporated with our free Bluetooth control MW Connect app, IOS and Android compatible; Adjust individual heat levels with your Smartphone for up to 4 different heated garments EASY CARE: Machine washable. The heating elements are designed for machine wash cycles. Advanced fabric and heating elements are safe for hand and machine washing.