What is the difference between SPT-1 and SPT-2 Christmas light cords?

When shopping online for Christmas light cords you might have noticed SPT-1 and SPT-2 specifications.  You’ll see that specification when you are shopping for C7 and C9 Christmas bulbs and cords. This spec is simply an indicator of the thickness and durability of the insulation.  Most of the time, Christmas light cords don’t list this… Read more… What is the difference between SPT-1 and SPT-2 Christmas light cords?