These two advertisements are for a mouse produced in Berkeley, California by designer Jack Hawley. In 1971 and 1975, Hawley had worked at Xerox PARC on refining the mouse designed by Douglas Engelbart; he later founded his own company, the Mouse House, to manufacture mice based on those designs. The advertisements' emphasis on expertise, the mouse's name (the scientific-sounding X063X), and a $400 price tag all suggest that these mice were intended mainly for scientists and engineers.
When they began work on a mouse design for Apple Computer, engineers at Hovey-Kelley examined some mice built from Hawley's design. They found it expensive, over-constrained, and too fragile for ordinary users.