Originally developed in the 1960s as the Herman Harrow, the Superharrow 3960 is the heaviest, most aggressive series of harrows from Summers. It offers 26-inch-long, 9/16-inch-diamater teeth that are oil tempered and spring-mounted with 2.4-inch effective spacing and 16-inch spacing between bars. Each section is 6 feet wide for superior penetration and increased ability to follow ground contours.