OVERVIEW: Individual Iron Zero Friction are also safe for golf course mowers. They are constructed of biodegradable corn starch and other natural ingredients. Zero Friction�s unique design drastically reduces the contact area between the tee and ball. This reduction in surface area decreases the amount of friction producing longer, straighter drives. Independent testing proves that with a 100 mph swing speed, a golfer can gain up to 4 yards of distance and over 5 yards of accuracy.