RevitLookup is a free, open-source add-in for Revit, which you can use to explore the Revit API.
You will find it invaluable for working out which Revit element properties you can use in PropertyWizard.
In this post, I am going to explain how to download and install RevitLookup, and then in future posts I’ll explain how to use it with PropertyWizard.
How to download RevitLookup
RevitLookup is maintained by Jeremy Tammick of Autodesk, on GitHub:

https://github.com/jeremytammik/RevitLookup
However, GitHub just hosts the source-code for the add-in. To install it in Revit, you need a compiled version. These are available here:

https://lookupbuilds.com/index.html?prefix=releases/
You can see that the top four entries are the latest versions of the add-in for Revit 2016 to 2019.
Each build is stored as a compressed 7zip file, so you will need a copy of 7zip to unpack them.

Within each build package there are two files:
- RevitLookup.dll, which is the compiled code of the add-in
- RevitLookup.addin file, which is the ‘manifest’ file for the add-in
How to install RevitLookup
To install RevitLookup, place the .dll and .addin for each Revit version in the relevant Addins folder on your computer:
C:\ProgramData\Autodesk\Revit\Addins\<RevitVersion>
When you restart Revit, you should find the Revit Lookup button on the Add-Ins tab of the ribbon:

Other options for installation
There are a couple of other options for more automated RevitLookup installation.
Troy Gates has installers for RevitLookup from Revit 2015 to 2018, published on his blog RevitCoaster:

http://revitcoaster.blogspot.com/2017/04/revit-lookup-2018.html
Harry Mattinson has an installer for RevitLookup from Revit 2017 to 2019, published on his blog BoostYourBIM:

https://boostyourbim.wordpress.com/2018/05/17/revit-lookup-2019-installer/
That’s all for this post: In future posts I’ll talk about how you can use RevitLookup to add more power to your PropertyWizard formulas.