Choose Toolbox items, adding to toolbox, which dll?

This must be a simple question:

I have created a classlibrary with some components.

Now when I select 'Tools, Choose Toolbox items..' and select 'Browse' to find my library, should I use the dll in the 'bin' folder or the one in the 'obj' folder

Also, I assume, I should use the 'Debug' version. Right