Water-Resistance
AirPods Pro are the first of the Apple-branded wireless headphones to feature an actual Ingress Protection (IP) rating. More specifically, AirPods Pro are said to carry an IPX4 dust- and water-resistance rating.
While Apple doesn’t specify what that means, the IP standards indicate that devices with an IPX4 rating can withstand splashing water from any direction. While AirPods Pro aren’t rated for submersion (and you shouldn’t take them swimming), they should feature much better water/sweat resistance than past AirPods.