First coined in Daniel J. Siegel’s The Developing Mind, the window of tolerance refers to each individual’s “window” of emotional activation, inside which they are comfortable and can function optimally. Everyone’s window is unique, and every window has the potential to change—to narrow or widen. Widening one’s window of tolerance for certain emotions can increase the capacity to live more fully and freely within that window, and may be said to be the central work of therapy. Individuals operating within their windows of tolerance can effectively cope with and come to enjoy and appreciate their emotions. With this laminated card, Dr. Siegel’s celebrated concept is made available in a convenient, easily accessible format. With a visual depiction of the window of tolerance on one side of the card and a summary of the key concepts on the other, mental health practitioners will find this product especially useful in exploring the window of tolerance with their clients.