Quick Features - & 127777;& 65039; 3-Level Temperature Control (35-55°C) - & 9889; USB-Powered (5V/2.4A compatible) - & 128293; 30-Second Heat Activation - & 128170; Targeted Heating: Knees, Back & Waist - & 128737;& 65039; Built-in Safety Protection - & 129530; Machine Washable Product Description Stay warm and comfortable in any winter activity with our advanced USB heated thermal underwear. Designed for both men and women, this innovative base layer combines premium comfort with smart heating technology. Advanced Heating Technology - Rapid 30-second heat activation - Three temperature settings with LED indicators:   - High: 45-55°C (Red LED)   - Medium: 40-50°C (Blue LED)   - Low: 35-45°C (White LED) - Strategic heating zones: knees, back, and waist - 6-7 hours of continuous heat with 10000mAh power bank (not included) Safety & Comfort - Premium blend: 95% Cotton + 5% Spandex with carbon fiber heating - 5V safety voltage with overheat protection - Auto temperature regulation - Machine washable with protective features - Compatible with standard USB power banks Perfect For - Winter Sports: Skiing, Snowboarding - Outdoor Activities: Hiking, Hunting, Fishing - Daily Use: Walking, Running, Commuting - Health Benefits: Aids circulation, helps with joint stiffness - Medical Conditions: Suitable for Raynaud's disease, arthritis Specifications - Available Colors: Black, Gray - Sizes: S to 5XL - Season: Autumn/Winter - Power Source: Any 5V/2.4A USB power bank (not included) What's in the Box - Heated Thermal Top Note: Battery life varies based on temperature setting and power bank capacity. For optimal performance, use a 10000mAh or higher capacity power bank. table { width: 100%; border-collapse: collapse; margin: 20px 0; background-color: e8f5e9; font-family: Arial, sans-serif; } th { background-color: 2e7d32; color: white; padding: 12px; text-align: left; border: 1px solid 81c784; } td { padding: 10px; border: 1px solid 81c784; } h2 { color: 2e7d32; margin-top: 30px; } .note { font-style: italic; margin-top: 20px; color: 555; } Men's Tops Size Chart Size/Height Length Chest Sleeve Weight (lbs) M/65" 24.8" 37.8" 21.9" 110-121 L/67" 25.6" 39.4" 22.4" 132-143 XL/69" 26.4" 40.9" 23.1" 154-165 2XL/71" 27.2" 42.5" 23.6" 171-176 3XL/73" 28.0" 44.1" 24.2" 182-193 4XL/75" 28.3" 45.7" 24.6" 198-209 5XL/77" 28.7" 47.2" 25.0" 215-226 table { width: 100%; border-collapse: collapse; margin: 20px 0; background-color: e8f5e9; font-family: Arial, sans-serif; } th { background-color: 2e7d32; color: white; padding: 12px; text-align: left; border: 1px solid 81c784; } td { padding: 10px; border: 1px solid 81c784; } h2 { color: 2e7d32; margin-top: 30px; } .note { font-style: italic; margin-top: 20px; color: 555; } Women's Tops Size Chart Size Length Shoulder Chest Hem Height Weight (lbs) S 21.1" 13.4" 31.5" 32.3" 59"-63" 88-99 M 21.9" 13.8" 33.1" 33.9" 63"-67" 99-121 L 22.6" 14.2" 34.6" 35.4" 65"-69" 121-132 XL 23.4" 14.6" 36.2" 37.0" 66"-70" 132-143 2XL 24.2" 15.0" 37.0" 38.6" 67"-71" 143-165 3XL 24.6" 15.4" 39.4" 40.2" 68"-72" 165-187 4XL 25.0" 15.7" 40.9" 41.7" 68"-72" 187-198 Note: - All measurements have a tolerance of ±0.4-1.2 inches - These measurements are for reference only.