These large size warmers are extra energy packed to give you up to 24 hours of continuous warmth. Take these large warmers on your longer trips to keep you warm while hunting, skiing, snow boarding, or even working. SHIPPING NOTICE: These will be shipped Via USPS Priority Mail if ordered by themselves. Shipping cost to you will be adjusted to actual cost. Please do not pay attention to the higher UPS shipping rates you see during Chekout.