The surface area of the core (mm2).
The IP (Ingress Protection) code indicates the degree of protection against ingress of moisture and solid objects. The code consists of two firures. The first figure indicates the protection against objects and dust: IP 0x - not protected IP 1x - protected against objects with a diameter above 50 mm IP 2x - protected from objects with a diameter greater than 12 mm (touch safe) IP 3x - protected from objects with a diameter greater than 2.5 mm IP 4x - protected against objects with a diameter greater than 1 mm IP 5x - protected against dust ( dust ) IP 6x - dustproof
The second figure indicats the protection against water: IP x0 - unprotected (plain) IP x1 - Protected against dripping water (drip) IP x2 - Protected against dripping water when tilted to 15 degrees IP x3 - protected against spraying water (rain tight) IP x4 - protected against splashing water (splash proof) IP x5 - protected against water jets (splashproof) IP x6 - protected from rainstorms IP x7 - protected against accidental immersion (30 minutes to 1 meter deep) (waterproof) IP x8 - protected from stay under water (pressure proof)