Gauge Series Features: Black face gauge with magnified clear lens Black trim ring with black housing Red illuminated needle with full sweep Electronic Gauges has Opening Sweep Movement 7 color LED illumination number glow and color recall technology (Gauge will return to previous color when vehicle is turned off) Fast and slow automatic color changing modes Gauge visor Mounting and Installation hardware Instructions 2 1/16th inch gauge or 52 mm diameter Vacuum Gauge Includes: T-Fitting and Hose Kit All mounting hardware Gauge Visor Detailed installation instructions Reads: -30 to 0 Vac Mechanical Gauge Free Tech Support 12 month limited warranty This Vacuum Gauge measures the engine’s vacuum and compression level between 0-30 mmHG. This can alert you of low vacuum levels in your car before costly problems arise. A normal operating vacuum level is between 18 and 22, which means your engine is running with good fuel/gas economy. A vacuum level below 18 may indicate a leak in your vacuum system, which ruins crucial car operations such as timing and specific sensors to keep your car running efficiently. For maximum engine power performance, a level higher than 22 indicates the engine is running at its peak performance. Important Note: This item is not vehicle specific. It is compatible with a wide range of applications and is therefore displayed on our site regardless of your vehicle selection. Please review the specifications and verify compatibility prior to placing your order.