PVC (Polyvinyl chloride) is extracted from the polymerization of vinyl chloride monomer. We can classify PVC into two large groups, rigid PVC and flexible PVC.

Rigid: used for the construction of tubes, pipes, containers, tool accessories, parts of parts, blinds, windows, etc.
Flexible: Corrugated tube, traffic signs as cones. irrigation hoses, curtains for refrigerators, footwear, medicine, etc.

This material begins to soften at 80 ° C and melt at 140 ° C. Thanks to these and other properties, PVC is a recyclable material.

Among the main characteristics of PVC we find:

• Different degree of hardness.
• Waterproof.
• It does not corrode.
• It is moldable if it is subjected to high temperatures.
• Good electrical insulator.
• It is a very resistant material.
• Stable and inert.
• Good mechanical and impact resistance.
• High resistance to abrasion.
• Strong and lightweight.
• Good thermal insulation.
• It is odorless, tasteless and harmless.

There are several ways to connect electronic devices to each other; cables, infrared, etc. Bluetooth technology is one of them and enabling wireless transmission of voice and/or data between devices by radio frequency.
It is a technology of radio waves at short range (2.4 GHz) whose objective is the communication between devices such as computers, smartphones, tablets, printers, headsets and other dispositives hand.
Bluetooth is called the communication protocol specifically designed for low-power devices. These devices can be classified according to their transmission power:
- Class 1: 100 mW, maximum range approximately 100 meters.
- Class 2: 2.5 mW, approximate maximum range between 5 and 10 meters.
- Class 3: 1 mW, maximum range approximately 1 meter.

We can also classify this technology by standard. All these versions have backward compatibility, ie, it allows the latest standard is compatible with all previous versions.

- Version 1.2: 1 Mbit/s
- Version 2.0 + EDR: 3 Mbit/s
- Version 3.0 + HS: 24 Mbit/s
- Version 4.0: 24 Mbit/s