What is the difference between NOD/SCID and SCID mice used in experiments?

So I understand that mice that are severe compromised immunodeficient (SCID) do not have any T or B lymphocytes and people researching using these mice are interested in the response without the adaptive immunity, but what is the purpose of the NOD/SCID mice? I understand that non obese diabetic (NOD) mice are susceptible to autoimmune diabetes where the insulin beta cells are destroyed, but why do people use the NOD/SCID mice in combination? And when do the cells become self reactive in the immune response, I thought it was through antibodies and if that's the case, how can SCID mice even become NOD through autoimmunity?