Buy for Wireless Charging
When you put the AirPods in the case they start charging. But you need to plug the AirPods case in to charge with a Lightning cable if you own the original model. Now you can get Airpods with wireless charging. This allows you to simply place the AirPods case on a Qi wireless charger to start charging your AirPods up.
You can buy the AirPods wireless charging case as a standalone upgrade for $79, and that makes some sense if you just bought first-gen AirPods, but for most shoppers, this is a feature that you should consider when you buy new AirPods, not as an upgrade to the existing model.
A small LED indicator on the front of the AirPods wireless charging case lets you know when the case is charging at a glance and you can ask Siri about battery life as well.
You can use this with Qi wireless chargers, like the one you use to charge your iPhone.