The Lectra Sox have been reinvented with 1990's technology. The heat output has been increased and the wires and heating unit are now buried in recessed channels in the socks making them invisible to the wearer. A new wool blend has been formulated to provide increased warmth and maximum wicking. The "D" cell alkaline battery provides 4-6 hours of continuous heat, more when used intermittently. Safe and comfortable, the Lectra Sox work even when wet. Color: grey/maroon.