HeatMax Survival Heat Provides up to 15 hrs of real heat, New reflective inner liner for emergency signal use Cold weather survival tips included on inside and back, special bag allows warmer to be reused to provide full benefit of the 15 hours of heat Individually sealed in airtight package to guarantee a shelf life of six years Portable (No wires or batteries), odorless, disposable, safe Nontoxic, nonflammable, enviromentally friendly, contains all natural ingredients