Jawbone has unveiled its latest tracker with heart-rate monitoring. Here's everything you need to know about the Jawbone Up3 price, features and specifications. (Here's our round up of the best activity trackers currently available.)

Jawbone is fairly well known for its Up fitness band, and more recently, the Jawbone Up24, reviewed here. Here we explain everything you need to know about the third-generation Up3, including its price, release date, specs and how it works.

Jawbone Up3: release date

The Up3, as you'll already know if you've been waiting patiently for it since last year, has been hugely delayed. It was originally meant to launch in Winter 2014/2015, but due to problems with water resistance during manufacturing, it will now launch in the UK in mid-July 2015.

Jawbone Up3 release date, price, specs UK

Jawbone Up3: price

The Up3 is the most feature-packed tracker Jawbone has made to date, and it carries a premium price of £129.99. It will be available in two colours called Black Twist and Silver Cross (not to be confused with the pushchair manufacturer).

Jawbone Up3 release date, price, specs UK

Jawbone Up3: features

The aim of the Up3, Jawbone said, was to create the most powerful tracker in the smallest possible design.

Heart rate

To this end, the Up3 has more sensors than the Up24 and can measure your resting heart rate. It will do this just before you wake up and after you've gone to sleep. Instead of using optical sensors, as with the new Fitbit Charge HR and Surge (and other fitness trackers) the Up3 will use electrical contacts (bioimpedance sensors) pressed against the skin which measure conductivity.

 It will not monitor heart rate constantly as the new Fitbit trackers do, though.

The aim is instead to plot your resting heart rate over time to allow you to gauge how healthy your heart is. Measuring the resting rate when asleep avoids it being affected by other factors such as caffeine, exercise and even stress.

Advanced sleep

Jawbone is one of the few companies that does sleep tracking well, but the Up3 won't rely only on a basic accelerometer to detect how well you're sleeping. It has sensors for both skin and ambient temperature, plus a new tri-axis accelerometer.

It can now detect sleep stages: REM, Light and Deep sleep, which means the app can better inform you how well you're sleeping.

Auto activity detection

The new sensors have been put to use in other ways too. The Up3 can recognise different sports, such as running, cross training, hiking, tennis and even Zumba. It will also learn over time to classify sports which are harder to recognise including swimming, cycling and weight-lifting.

Jawbone Up3 release date, price, specs UK

Jawbone Up3:  Specs and design

The look of the Up3 is different from the Up and Up24. The Silver Cross is almost a quilted design which is likely to be bought by women, leaving men with the black version that has a texture similar to the Up24.

The design of the band has changed, too. It now uses a more traditional watch-style buckle rather than the cross-over flexible design with no clasp at all.

It measures 220x12x3-9.3mm, and is described as "one size fits most". It weighs just 29g, which is amazingly light, and the battery is said to last 7 days between charges, which take just over an hour and a half via the magnetic USB charging cable.

The Up3 is designated as merely "splash proof" rather than suitable for swimming or bathing – much the same as with the Fitbits and Apple Watch. See Apple Watch vs Fitbit.

Wireless synching is via the usual Bluetooth 4.0 LE.

There's no display, which will frustrate anyone hoping to see stats on their wrist. Instead three LEDs indicate sleep (blue), activity  (orange) and notifications (white).

The bioimpedance sensors measure heart rate, sweat and galvanic skin response (GSR) which is essentially a way of measuring the electrical conductance of the skin, which varies according to the amount of moisture on the skin.

The band is made from TPU and has anodised aluminium and tin-coated stainless steel.

See also: Jawbone Up24 review