Product Description: 1. Perfect Fitment: Compatible with Cummins diesel engines and other diesel engines equipped with Compucheck ports. 2. Pinpoint Fuel System Diagnostics: Features a high-precision 300 PSI gauge for accurate pressure readings on fuel system, helping you quickly identify operation issues and get it solved. 3. Effortless & Flexible Testing: Designed for convenience with a 6-foot hose and a clear 3-1/2" dial gauge. Easily perform tests under the hood or on-road driving for real-time diagnostics. .