Object of Focus for Mindfulness (Non-judgment)

In the context of modern mindfulness, one should pay attention to awareness non-judgmentally. I have tried this, and wondered whether it is possible to do so without an object, e.g. the breath. Jon Kabat-Zinn, founder of this movement in the West, advised in one of his talks/books that one should keep with the object for a long time, even years. **What is the effect of attending to awareness without any object, merely being non-judgmental to what arises? Is there such a thing?**