Over the next four weeks, Baseline will bring you four of the best workout tracking wrist accessories. This week, it's the Fitbit Flex:

Cost: $99

Sizes: Large (6.3–8.2”) and small (5.5–6.9”)

Width: 0.6”

Colors: Variety

Battery life: Five days

Features:

The Fitbit Flex is understated and simple looking. Outside of the rainbow of band colors offered, it’s more utilitarian in appearance than stylish tech wear. The thin, smooth silicone, watch-like band has a two-prong clasp that can take some practice closing. The almond-sized tracker is a removable piece housed in the center of the band.

There’s a small rectangular window on the band that reveals a portion of the tracker that displays up to five circular indicator lights. Each light represents 20 percent of your progress toward your pre-determined daily goal of either steps, calories burned, distance, or active minutes.To get the meaty data on your activity you need to consult the accompanying app or profile on the Fitbit website. With their clean, intuitive designs and easily digestible info both significantly enhance the Flex’s value. You get access to numbers and graphs that chart and compare all your metrics—including sleep—over days, weeks, and months.

Buy it:Fitbit.com