This heavy duty string of lights is part of the Commercial Grade A series, and requires at least one unit of the Commercial Grade A power cord, item C-APCORD-1G, to function. There are 25 LED lights on the strand. Being LEDs, these warm white lights use substantially less power than other string lights and are much more durable. Each bulb has a faceted cap on it that is meant to resemble the traditional C-7 Christmas light. Never before has it been safer to have these as part of your Christmas decorations. These lights are great for Christmas and Valentine's Day too. The green wire is 20 gauge. The total strand length is 25', including an extra long 12" between bulbs, a 12" end cord and a 12" lead cord. You can connect up to 10 strands together using the end-to-end connectors. UL listed for indoor and outdoor use. REQUIRES ONE UNIT OF C-APCORD-1G TO FUNCTION PROPERLY.