Apple is working on at least two new versions of its wireless AirPods earphones, according to a Bloomberg report this morning, with plans to release one as early as this year, and the second as early as next year. Each of the new models is expected to bolster existing features rather than radically changing the current, apparently successful formula.

Developed under the code name B288, the first new AirPods version is said to let users evoke Siri by saying “Hey Siri” rather than tapping on the earphone’s stem. It’s unclear whether Apple’s AI assistant Siri will gain additional functionality for AirPods or largely continue to be used for changing tracks, volume, and play/pause status.

B288 will also include “an upgraded Apple-designed wireless chip for managing Bluetooth connections.” The current AirPods model uses Apple’s W1 wireless chip, delivering five hours of battery life on a charge, and is compatible with Bluetooth 4. Apple has recently added Bluetooth 5 to recent iPhones and the HomePod, suggesting that the new AirPods will follow the same path.

The second new AirPods model will be designed to “survive splashes of water and rain” but is not intended for full submersion in water. Current AirPods are generally capable of withstanding sweat when used for indoor workouts but can be damaged when used in the rain or dropped in water.

Additionally, Apple’s website notes that an “optional wireless charging case [is] coming in 2018,” and Bloomberg mentions the case without discussing Apple’s plans for it. This case was originally shown during a sneak peek at AirPower, an Apple-developed charging mat compatible with last year’s new iPhone and Apple Watch models. In addition to being offered as an additional purchase for current AirPods users, the case might be bundled with one or both of the upcoming AirPods revisions, potentially pushing up the current $159 asking price.

Apple does not break out sales of AirPods in its lineup, but the wireless earphones are generally believed to be popular. The product was extremely difficult to get in the months following its December 2016 release, in part due to initial production constraints, and has been included in Apple’s growing Wearables category alongside the Apple Watch.