These lenses exceeded my expectations, they are very clear and durable. They make reading the gauges so much easier. They are an essential item for any Industrial and Scientific setting. The only downside is that they can be a bit tricky to install, but patience and careful hands will get the job done right.
Pros
Clear lenses allow for easy reading of regulator gauge
Cons
Without proper installation, lenses may become dislodged during use
This set did a great job replacing two lenses on two gauges but as they say it is for 1/4 turn gauges and it doesn't really work spiral gauges when you add a few drops of epoxy. Don't buy them for screw-on lens gauges hoping they will work. Definitely 5 STARS if used on the right sensor.