Apple revealed a new S4 chip for its Apple Watch Series 4 product just announced at the the company’s event on the Apple campus.

The new watch has twice as much processing power as the previous one, and it has 64-bit processing and two cores.

Apple designs its own chips to keep more of the profits inside the company, rather in the hands of its competitors like Samsung. But once those chips are designed, Apple uses TSMC to manufacture the chips. It designed its A series chips for its iPhones and tablets, while it has created its S series processors for the Apple Watch.

Each time Apple creates a new major product line, it also creates a design for a new family of processors. And at each event, Apple touts the competitive advantage it gets from designing its own chips for its flagship products. Apple still uses Intel’s x86 processors in its family of Mac computers. The watch has an electrical heart sensor to detect your heart rate.

It also has a new gyroscope that can detect things like falls. The watch can do functions like take an electrocardiogram (ECG), send you alerts if you have an elevated heart rate, and help you with other health issues. It can detect an irregular heart rate. You can take an ECG in 30 seconds, and it is FDA approved. The watch also has a louder speaker, and the battery has 18-hour, all-day battery life.

Many of the features are possible thanks to the processing power of the chip.

Read all the latest stories from Apple's Gather Round event