The One Probe 9minecraft FAQ
6 questions players actually ask, answered.
What does 
The One Probe add to Minecraft?
It adds helmet-mounted probes that display information about the block or entity the player is looking at. The overlay is configurable and there is an in-game readme guide.
How do you get the probe overlay to appear?
You wear a helmet that has a probe attached, such as the Iron, Golden, or 
Diamond Helmet with Probe. The overlay then shows details about whatever you are looking at.
Diamond Helmet with Probe. The overlay then shows details about whatever you are looking at.What helmet variants with probes are available?
There are Iron, Golden, and Diamond Helmets with Probe. Each combines a helmet with the probe functionality.
Is there a standalone version of the probe that isn't a helmet?
Yes, 
The One Probe (Bauble) provides the probe as a bauble rather than a helmet. There is also The One Probe item and 
The Creative Probe.
The One Probe (Bauble) provides the probe as a bauble rather than a helmet. There is also The One Probe item and The Creative Probe.What is 
The One Probe Read Me for?
It is an in-game guide item that explains how the mod works and how to configure it. You can use it to learn about the overlay settings.
Can the probe overlay be customized?
Yes, the overlay is configurable. The Read Me item and the mod's config options let you adjust how information is displayed.