... , so that the gauge can be used longer.Specification:1. Type: YRF 2. Accuracy rating: 2.53. Case Diameter: 50mm=2 ... or back connection6. Thread Coupling: M20x1,5, BSP, NPT, BS, UN...7. Ambient Temperature: -10~70°C 8. Relative humidity: ≤80 ... and 50 bar the red light on switch lighted. Waterproof type CNG pressure gauge