IP stands for ingress protection and is a way of measuring how protected an electrical item is from solids (the first number) and liquids (the second number), so it's important to understand what to look for when you're after a waterproof extension lead. Pressure washers and vacuum cleaners are a perfect way of cleaning your car, but unless you're prepared to risk a cordless, battery-operated example for your cleaning duties you'll be bound to the operating radius offered by the manufacturer. There's little point risking it with a normal extension lead (especially in the case of the pressure washer), because of how temperamental British weather can be. What you need for your pressure washer and vacuum cleaner is a proper, IP certified waterproof extension lead. What is IP?