This black colour necklace has a satin like thread wrapped around a hollow rubber tube.
Size: 8 x 49mm (19 inches)
You will need to glue a bell cap to each end of the cord to make it into a necklace and then jump rings and clasp.
You could also cut the cord to make it a bracelet.
When the cord delivered it will be look bent and out of shape, as the tube is rubber when you make into a necklace these bends will work themselves out and and can be corrected by gently adjusting the shape with your fingers. Do not move your fingers up and down the cord as this could unwind the thread on the rubber tube