Apple unveiled a new version of its digital smartwatch, Apple Watch, on Wednesday, making the device waterproof and adding GPS tracking to a device that didn’t sell as well as many analysts expected in its first 18 months on the market.

Introduced ahead of Apple’s new line of iPhones, the new Apple Watch Series 2 is the first overhaul of the smartwatch line since the tech giant started selling the device in April of last year. The series 2 watches will start at $369, up from the first model’s $349 starting price. But Apple said it would continue selling the original model, now dubbed series 1, with an upgraded processor for $269.

Although Apple upgraded the device in several ways, it did not make the watch noticeably thinner or lighter than the original model. Pre-orders will start on Friday and the new watches will arrive a week later, on September 16. A special model co-branded with Nike nke and aimed at runners will arrive in late October.

The new Apple Watch can be used while swimming and submerged as deep as 50 meters compared to the prior model, which was just “splash-proof.” The built-in GPS means runners can track workouts without needing to carry a phone. And the series 2 will be available in a new, third case material, pearl white ceramic, in addition to the original stainless steel and aluminum versions.

The original Apple Watch debuted to mixed reviews, with some finding the device’s interface confusing. The revamped smartwatch will come with Apple’s WatchOS 3 software, introduced in June and meant to simplify and speed up the user interface. On Wednesday, Apple also said the watch would get a special version of Pokemon Go.

See all of Fortune’s coverage of Apple’s event

The revamp comes as Apple aapl is losing ground to Fitbit fit in the market for wearable smart devices. Fitbit, which sells mostly more limited and less expensive digital wristbands, captured 25% of the market in the second quarter, the same share it had a year earlier, according to International Data Corp.

But Apple saw its share drop to 7% from 20% last year as sales of its watch tumbled ahead of the new models.

Thus, it was not surprising much of the emphasis in Wednesday’s unveiling was on fitness tracking features, the main focus of Fitbit’s devices. “We think Apple Watch is the ultimate device for a healthy life,” Jeff Williams, Apple’s chief operating officer, said as he introduced the new device.

Even the new Pokemon app included a step tracker and measured calories burned.