Pebble 2, Pebble Time 2 and Pebble Core: Two watches and a button (photos)

The Pebble Core is Pebble's newest wearable gadget, and it's not a watch: It's a GPS-enabled clip-on music player and fitness tracker.

Pebble also has two new smartwatches on the way in September in the Pebble 2 and the Pebble Time 2.

The Pebble 2, Pebble Time 2 and Pebble Core together. The Core can used with a Pebble watch, or separately.

The Pebble watch can't play music, but the Core can as it's a stand-alone Spotify-enabled player.

The Pebble Core runs on Android, and can store music on 4GB of memory. It has a headphone jack and Bluetooth.

Two touch-sensitive areas act as smart buttons, and can be programmed to do different things.

The Core also has built-in GPS, and a SIM card slot to work as a 3G-enabled device. Its battery lasts for 9 hours of music playback, or days on standby. And it charges wirelessly via the Qi standard.

The Pebble Time 2 (left) and Pebble 2 (right) both arrive in September, and add one big new feature: Optical heart rate tracking.

The Pebble Time 2 has a larger color display, but otherwise looks just like the Pebble Time Steel. The Pebble 2 is a redesign of the original Pebble.

The Pebble Time Steel in the middle looks nearly the same to the Pebble Time 2 on the left.

At $130 in the US (which converts roughly to AU$180 and£90), the Pebble 2 adds heart rate, plus an onboard microphone for voice replies.

The Pebble 2's screen is black and white, but the design has a lot of charm.

The Pebble 2 in all its available colors.

A look at the larger screen and improved pop-up notifications on the Pebble Time 2.

The Pebble Time 2 comes in gold, black and silver.