There's actually bespoke pressure washer codes for the IP system, suffixing with a K https://www.polycase.com/techtalk/waterproof-electronic-enclosures/ip66k-r

There's actually bespoke pressure washer codes for the IP system, suffixing with a K https://www.polycase.com/techtalk/waterproof-electronic-enclosures/ip66k-rated-enclosures.html https://www.polycase.com/techtalk/waterproof-electronic-encl... That said even ip66 is supposed to be resistant to 'jets' of water, like ~hose pressure. Also, fwiw, I've never seen these used on prebuilt ebike components.