If you're ballasting your tires, regular monitoring of your tire pressure is essential. Slime's Air & Water Pencil Tire Gauge was designed specifically for ballast tires, and easily clips onto a pocket, so you'll always know where it is. 

• 5-50 psi
• Especially designed for tires with air and water inside
• Great for tractors and other ballasted tires
• Chrome gauge body
• 4-sided tongue measures psi, kPa and bar
• Built in metal pocket clip
• Tire sensor safe

• You can improve your gas mileage by around 3.3% by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4% for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer.