Martel Model # T-140-300-KIT High accuracy gauge or differential capability Rugged, dust tight, water-resistant case Isolated SS sensors on 300 PSI and 3,000 PSI units Easy to read Super-Twist LCD Intuitive controls make operation easy, even for infrequent users Powered by a common 9 Volt alkaline battery Supplied in full rubber boot > Each Unit Includes Protective Rubber Boot Batteries NIST Calibration Certificate Instruction Manual