Product Details: The Donaldson 1/8"-27 NPT Informer Restriction Gauge is the perfect tool for monitoring filter restriction readings. This gauge is designed to be resistant to weather, corrosion, dust, vibration, breakage, dirt and dust, ensuring accurate readings. With this gauge, you can easily replace filters based on restriction readings, helping to reduce your maintenance costs significantly. The gauge meets all the necessary safety and performance standards, making it a reliable and durable choice. FleetPride is your First Click in Heavy Duty®.