IP0X: The product is not protected against any physical contact or objects.
IP1X: Only protected from objects larger than 50 mm. You won’t accidentally stick your hand into this product, but you can still easily get, say, your finger in. You probably shouldn’t.
IP2X: Protected from any object larger than 12.5 mm. This now includes fingers.
IP3X: Protected from things above 2.5 mm, which includes most tools and thick wires.
IP4X: Protected from anything bigger than 1 mm.
IP5X: Dust resistant. Some dust may get through, but it won’t be enough to damage the product.
IP6X: “None shall pass!” This product is fully dust tight.
IPX0: The product offers no special protection from water.
IPX1: Can resist water that drips vertically onto the product.
IPX2: Can resist water that hits the product at a 15° angle or less.
IPX3: Can take water sprays of up to 60°.
IPX4: Is resistant to water splashes from any direction.
IPX5: Can resist a sustained, low-pressure water jet spray.
IPX6: Can resist high-pressure, heavy sprays of water.
IPX6K: Can resist water jets of extremely high pressure. Rarely used.
IPX7: Can be submerged up to 1 meter in water for 30 minutes.
IPX8: Can be submerged deeper than 1 meter. The exact depth is specified by the manufacturer.
IPX9K: Resists high-pressure, high-temperature sprays at close range. A very special case that’s dictated by a separate standard. Rarely used.