CRYSTAL ENGINEERING Crystal Engineering XP2i Digital Test Gauge 15 psi Gauge Range Accuracy: 0.1% of Reading (20-100% of Full Scale), 0.02% of Full Scale (0-20% of Full Scale), 5 Digit Display, 1/4" NPT Bottom Connection, DB-9 Connector, Intrinsically Safe, Includes A2LA Accredited ISO 17025 Calibration Certificate