If you’re ballasting your tires, regular monitoring of your tire pressure is essential. Make checking your air pressure a whole lot faster with Slime’s Air/Water pencil tire gauge. It was designed specifically for ballast tires and easily clips onto a pocket, so you’ll always know where it is. Make sure your tires are up to snuff with the Air/Water Pencil Tire Gauge.Especially designed for tires with air and water insideChrome gauge bodyFour-sided tongue measures psi, kPa and barBuilt-in metal pocket clipTire sensor safe