Hydraulic pressure gauges and manometers with glycerin (G-series). Calibrated on a double reading scale in psi and bar. All sensitive parts of the manometers are waterproof, the glycerin cushions the pressure points for increased durability. Includes a burst guard and a pressure-equalizer membrane. Safety valves for manometers or needle valves are recommended for applications with high cycles. Hydraulic pressure gauges and manometers with high cycles (H-series). Calibrated on a double reading scale in psi and bar. Ideal for many applications, especially when the number of cycles is high and the environment difficult. Safety valves for manometers or needle valves are recommended to isolate the manometer from the circuit when not in use.