To rate and grade the resistance of enclosures of electric and electronic devices against the entry of liquids and dust, IEC 60529 was developed. It also rates how simple it is for people to get to any potentially dangerous components inside the enclosure. For electrical or technical equipment, enclosures with high IP ratings are necessary. Equipment’s performance may be impacted if liquid, moisture, or solid particles enter it.
As shown in the table below, all other series are IP68 except for the AS series, which is IP66.

Series	IP66	IP68
EN		ü
ES		ü
EN		ü
ES		ü
EN		ü
AS	ü