Bulk reel string lights provide commercial grade cords with weatherproof sockets. Spools of heavy-duty string lighting are often used for buildings, patios, backyards, bars, and restaurants. The commercial quality cord feature weatherproof sockets to withstand the element year-round. Bulk reel string lighting is perfect for larger projects and when longer lengths are needed. The 330 foot spools are available in three socket sizes — E26/medium, E17/C9 and E12/C7.