We've had six to seven sets of these lights on our christmas tree for years now. Possibly ten to twelve years with no problems. One of my sets lost a couple blues and greens, so I thought it time to get some replacements. After so much good service out of the others, I only felt right getting more of the same. Two sets to possibly cover a bigger tree. Can't say enough about the quality of these sets. Even the colors still match the older sets.