It is the "thickness" of the cable. The thicker it is, the more current it can handle without its temperature rising.

4 x 2.5

Intended for heavier loads, such as general-purpose sockets, power tools, ovens, or refrigerators. It can safely support single-phase power supply lines.

IP protection indicates the resistance of an electrical component to dust and water. The first digit (0–6) refers to protection against solid objects, from none to complete protection against dust. The second digit (0–9) refers to protection against liquids, from drips to full immersion or high-pressure water. For example, IP44 means protection against limited dust and water splashes, while IP67 means complete dust protection and immersion up to 1 meter.

Single-phase

The single-phase extension reel connects to a household or professional 230V AC supply. It is intended for low or medium power devices, such as lamps, computers, or tools. The operating current usually ranges between 10–16A. It is easy to use and transport, but cannot power high-power machines. It is recommended to use cables of suitable cross-section to avoid overheating.

Three-phase

Used in industrial applications with 400V AC power supply. It features three phases, neutral, and earth, and can power large tools, motors, or high-power machines. The current capacity usually ranges from 16A to 32A or more. It can be used for single-phase devices in case of need, but not the other way around. It ensures stable power supply and overload protection if used correctly.