Jawbone chose to surprise its customers with two new devices, the UP2 and the UP4. The Jawbone UP2 is a step down from the UP3 in terms of cost and features, but the Jawbone UP4 is the real showstopper.

The San Francisco company's latest creation, the Jawbone UP4, features advanced sensor technology that allows the tracker to not only monitor your resting heart rate, track your movement, record your diet and sleep, but now it also lets you make payments. Owners of the innovative Jawbone Up4 can use their arm band to make purchases using tap-to-pay where American Express contactless payments in the US are accepted. The Jawbone UP4 also offers all the perks of the UP3, such as sensors that can easily assess your Galvanic Skin Response, respiration, ambient temperature, and skin temperature.

While the touch-to-pay method is already being used for smartphones and smartwatches, such as Apple Pay, Jawbone is the first to create fitness band that offers the same feature. Now, instead of fumbling for your wallet, simply tap your wrist at checkout to pay for your morning coffee or for that bottle of water on your evening run. In fact, go ahead and leave your wallet at home; the Jawbone UP4 lets you depart from home with peace of mind. The best part is that the Jawbone UP4 costs much less than a smartwatch and the sleek design means its lighter too. In fact, the tracker features the same slim design as the Jawbone UP3.

The Jawbone UP4 boasts an encased NFC chip that allows for a credit card transaction. You can easily add your American Express card details to your Jawbone app, and for added security, the card number stored in the app is different from your real card number. According to fitness band mogul, the UP4 represents Jawbone's partnership with American Express and did not further comment on whether other credit card companies will be included in future fitness trackers.

The new wearable also works with the company's enhanced Smart Coach software. This function within the app provides more analysis on your daily routine. Rather than just showing the number of daily steps and hours slept, it also compares your stats to other Jawbone app users and notes where you can make progress. For example, if the Smart Coach notices increased activity levels after a set amount of hours slept, it will suggest a change in your bedtime.

Jawbone's latest masterpiece will set you back $199.99, which makes it just $20 more than the Jawbone UP3 and in our opinion, is well worth the extra few bucks. Read about what we think of the Jawbone UP3.