How to install and use?

If you have Asset Manager, then you can directly unzip the zip file and add the files to the directory Asset Manager is using.  For other Asset Managers, check their manual on how to add assets.  

I suggest to turn on Snapping to increment, absolute grid snap on Move, Rotate and Scale.  Press also the full stop on your keyboard and choose Active Element. This way you can easily snap the assets.  

Common shortcuts: 

Alt+D makes duplicates (linked) this way you can duplicate thousand time and will barely increase RAM usage.  

Alt+D, Shift+Z.  Now you duplicate, and move on the x-y plane. Handy for when you are in user perspective view and want to snap.  The asset will then stay on the same Z-Level.  

Recommended addons

These assets work perfect with Group pro.  Also works well with major addons like Hardops, Boxcutter, MESHmachine, DECALmachine, Fluent, etc.  

Can I sell these assets?

If you want to make assets like these, I recommend the MOAS-GEN addon. With the MOAS-GEN addon you can make unlimited assets.  The assets in this package (Modular Asset Pack No1) are is not for resale.