These 12 balls are in their 4 original plastic sleeves, which are bound together in what looks to be the original shrink wrap as shipped from the MacGregor factory.

In the 1980s Jack Nicklaus asked the MacGregor Golf Company to develop a ball for a small course his design company was laying out on Grand Cayman Island. The goal was to to make a golf ball that would travel about half as far as a normal ball, so the course could be built about half the length of a normal course.  MacGregor’s golf equipment engineers went to work and produced what was called the Cayman ball.

The Cayman ball is the same size as a golf ball. Instead of dimples it has a bramble surface and weighs approximately 24 grams, compared to the average 45 grams of a normal golf ball.  Together these restrict its distance to only slightly more than half the distance of a golf ball with a fast swing and a greater percentage with a slower swing. Also the Cayman ball floats!