the mice of the Sun3 keyboards are optical mice with two eyes (one red and one infrared).
the mousepads have blue horizontal and red vertical bars.
older keyboards have low resolution mice with big mousepads, newer ones have higher resolution mice and smaller pads.
only the Sun3/80 was sold with the newer type-4.
with the Type-5 keyboard Sun introduced one-eyed mice and ball mice.
adapter to use a type-5 or type-4 keyboard instead of a type-3.