60% Polyester, 30% Rayon, 10% Spandex Imported MIDWEIGHT PERFORMANCE BASELAYER - Made from a flexible polyester-rayon-spandex blend, this thermal baselayer is designed for layering under outerwear or wearing on its own in cool conditions. MULTI-ZONE HEATING SYSTEM - Two integrated heating panels across the back provide consistent warmth. In-seam thumbholes help keep sleeves in place while enhancing comfort. RECHARGEABLE BATTERY POWERED - Includes a 7.4V 2200mAh Powersheer lithium-ion rechargeable battery engineered exclusively to power compatible Fieldsheer heated garments. CUSTOMIZABLE HEAT CONTROL - Select from four adjustable heat settings using the integrated touch control button or manage temperature through the Bluetooth-enabled MW Connect app (iOS and Android compatible). EASY CARE DESIGN - Machine washable construction. Heating elements and fabric are designed for safe wash cycles.