This heavy duty string of lights is part of the Commercial Grade series, and requires at least one unit of the Commercial Grade power cord, item C-APCORD-1G~ to function. There are 25 LED lights on the strand. They are M5 lights~ also called mini ice lights~ with a faceted lens on each bulb. Being LEDs~ these pure white twinkle lights use substantially less power than other string lights and are much more durable. The green wire is 20 gauge. The total strand length is 8.5'~ including 6" between bulbs~ a 6" end cord and a 6" 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. POWER CORD IS NOT INCLUDED WITH THE SET.