Over the past two days, 13 startups have taken the stage at TechCrunch’s Hardware Battlefield. Now our editorial team has finished deliberating with the expert judges (seriously, expert) and chosen four finalists who will be competing for the big prize of $50,000, as well as a trophy that we like to call the Metal Man.

You can watch the presentations live on TechCrunch tomorrow (Saturday) at 2pm Pacific. Or, if you’re at CES, come by our stage in the entry hall to the Sands Expo.

Here are the finalists:

BloomLife

BloomLife has built a wearable device for pregnant mothers to help them track their contractions. It plans to add more data over time, with the goal of helping mothers better understand all the signals their body is sending during pregnancy.

Pillar Technologies

Pillar has developed smart sensors for construction sites, to help construction and insurance companies track the risk of fire, water and mold damage. The sensors are a little smaller than a shoebox, and are designed to be mounted throughout the site.

Siren Care

Siren Care weaves electronic sensors into clothing in order to monitor a person’s health. Its first product is a sock that can track temperature changes in feet for diabetics, which in turn helps them figure out when things are starting to go wrong and they need to go to the doctor.

Stratio

Stratio has built a portable device that can identify a pill in seconds. Called the LinkSquare, the device uses an ultra sensitive sensor to detect a pill’s “optical fingerprint,” the unique but consistent way each pill reacts to light.