Boost Gauge: Which One Is Right?

I would like to buy a boost gauge.
Do you have any recommendations for which one is particularly good?
Can I install it myself? Are there any instructions available?

Thank you in advance.

Hi.

... the measurement range is more important.
To prevent the indicator from exceeding the scale range or getting stuck at the maximum value when there are charging problems due to excessive pressure, I would choose a pressure range with a reserve of approximately 30-50%.

For the 90, 110, and 115 horsepower versions, a pressure of 1.5 bar is sufficient.
The 130 and 150 models have significantly higher boost pressures, so I would prefer a 2-bar gauge for those.

Even though a suction area indicator on the display for diesel vehicles might seem nonsensical at first glance:
In boost mode, this can help identify if the intake path is blocked (e.g., by leaves or a clogged filter), and in newer models with the "idle-anti-shake valve" (ALH, AHF, ASV, etc.).
It is possible to monitor their full opening and function immediately upon being placed.

As a side benefit, the negative pressure range can be used to test the vacuum pump by connecting the instrument to it (e.g., at a free port on the valve after the pump). It's quite interesting to observe the pressure loss/build-up, for example, when braking.