Holiday Lighting Outlet C9 Christmas Light String, Patio Event Lighting, Black Cord, 12" Socket Spacing, E16 (50') Professional sockets feature weep holes for trouble free damp weather performance. Popular 12" spacing between sockets Compatible with LED or incandescent bulbs with E17 Candelabra (17mm) bases. Use with E17 base bulbs including C9 and G50 & S11. Bulbs sold separately. SPT1 insulation provides 7 amp capacity. UL Recognized Components, rated for Indoor / Outdoor use. Max Run is 170 Sockets (212 Feet) with 7 Watt Incandescent Bulbs or 340 Sockets (425 Feet) with 1 Watt LED Bulbs Calculate for Amp Needs: # of Bulbs x Watts/Bulb = Total Watts Total Watts / 120 volts = Amp Needs