Uxcell M10 M4 Thread Sleeve Stud Pipe Connector Round Coupling Nut Gold Tone 4 Pack

What is this? Good hardware for connecting threaded pipes or threaded connectors together. Common accessories that are used on extending the screws or bolts. Suitable for installing chandeliers floor lamps table lamps and various DIY lighting fixtures with M10 thread. Are there any advantages of the product? Made of iron material surface electroplated with good strength and appearance. Two M10 thread holes on the bottom and top while two M4 thread holes on the side. How to use it? M10 and M4 thread easy to screw into threaded screws or bolts. What should I notice? Please check the thread size before buying.