respectively installed in the power cord a plurality of lamp assemblies respectively connected to the electric connectors to obtain the necessary working voltage and a plurality of electric extension wires respectively connected between the electric connectors and the lamp assemblies to transmit electricity from the power connectors and the lamp assemblies application_number US 78143201 A description referring to fig1 and 2 a decorative light string in accordance with the present invention is generally comprised of a power cord 10 and a plurality of electric connectors 12 respectively installed in the power cord 10 an electric extension wire 14 is respectively connected to each electric connector 12 to hold a respective lamp assembly 16 each electric connector 12 comprises a base 20 fastened to the power cord 10 the base 20 having a receiving chamber 22 and an outer thread 26 and metal contact plates 24 mounted in the receiving chamber 22 an respectively connected to the positive and negative poles of the power cord 10 a flexible insert 34 press fitted into the receiving chamber 22 of the base 20 and a screw cap 28 fastened to the base 20 to hold down the flexible insert 34 the flexible insert 34 is made of electrically insulative material for example plastics the screw cap 28 comprises an inner thread 30 threaded onto the outer thread 26 of the base 20 and a through hole 32 at the center of the top thereof for the passing of the electric extension wire 14 the electric extension wire 14 has its one end.