PIP Boss Therm™ Heated Glove Liner, One Size, Black Model 399-HG20PIP Boss Therm Heated Glove Liner, One Size, Black Model 399 HG20 The one size fits all heated glove liner helps keeps workers hands warm without sacrificing dexterity. Made to be worn under any glove, the Boss Therm heated glove liner is constructed from a 4 way stretch material that conforms to the hand and the heating element located on the back of hand warms the blood as it circulates through the hand. With three separate settings easily select