AIR Alert Tire Valve Cap Air Pressure Monitor w/Green and Red Indicators from US Solid EASY TO INSTALL: Simply inflate your tire to the proper pressure and screw the indicator onto the tire stem as you would a normal cap. SIMPLE TO READ: When the indicator is green your tire pressure is safe; when the indicator is red your tire pressure is low. BENEFITS: Under inflated tires will increase fuel consumption and wear on your tires. Using these valve caps will ensure you always have the proper air pressure in your tires. Proper air pressure will enhance road handling, improve fuel economy, and extend the life of your tires. QUANTITY AND QUALITY: You will receive 4 chrome metal indicators with each order. Each indicator cap will have a solid seal on your tire valve to prevent air leakage and may be used on any standard tire. SHIPS FROM CLEVELAND, OHIO, USA  EXPEDITED SHIPPING AVAILABLE