If you call .class.name on an instance of some class, the fully qualified name will be returned, module names and all. Consider the following example class:

module One
  module Two
    class Three
      ...
    end
  end
end

> One::Two::Three.new.class.name
#=> "One::Two::Three"

If you just want the unqualified class name; modules not included, you can use the #demodulize method provided by ActiveSupport.

> One::Two::Three.new.class.name.demodulize
#=> "Three"