Designed for stainless steel fermenting vessels, the Tilt repeater extends range of your Tilt hydrometer so it can reach more convenient locations where you might have a tablet, phone, or Tilt Pi plugged in for continuous automatic logging. Repeater can repeat signal from one Tilt at a time as long as signal is strong enough. It is waterproof and has a 6 month battery life with included USB-micro rechargeable li-ion battery. Repeater updates at least once every 2 minutes. Satisfaction guaranteed.