Loft

• Loft is the angle of the club face in relation to the shaft. Loft adds height and backspin to the ball. The average driver will have a loft of 10 degrees to 12 degrees. Clubs with less loft than average are used by better players because they roll farther after landing at a cost to ease of use. The ZL driver comes in lofts of 8.5, 9.5, 10.5 and 11.
  
  

Length

• The club has to fit the golfer, who must be able to comfortably line up the blade of the club parallel to the ground. The driver is the longest club in the bag and is swung in a more horizontal plane. Golfers can use drivers of many different lengths comfortably. ZL clubs come in a uniform length of 46 inches.
  
  

Swing Weight

• Swing weight is a arbitrary number combining the weight of the club and the location of the center of gravity within the club. The swing weight is listed on a chart published by the club industry by letter and number. However, the chart is based on older clubs and doesn't apply to modern clubs with graphite shafts. The shortest, lightest swing weight is A0 and the heaviest, longest swing weight is F9 -- theoretically. In reality, swing weights for almost all golfers lie between D0 and D4. The ZL club has a swing weight of D4 for all lofts.
  
  

Flex

• Golf clubs would be uncomfortable and inaccurate if the shafts were completely stiff. When a golfer swings his club harder, the shaft bends farther. Pro golfers hit the ball harder than average golfers, and tend to use stiffer clubs. Amateur golfers are more comfortable with a shaft that bends more than the clubs pro golfers use. The impact of club head and ball feels softer, with a more flexible shaft. Golf club manufacturers match flex with club head speed, based on the most comfortable stiffness for that group of golfers. When club head speed is between 70 and 90 miles an hour, the best shaft flex is Regular; between 90 and 100 miles per hour, it moves to Stiff, and over 100 miles per hour, it carries the designation "X" for extra stiff. The ZL clubs are available in regular and stiff.
  
  

Adjustable Head

• The head of the ZL will twist open, neutral or closed. The setting is intended to offset the driving faults of the golfer. The head of the ZL can be opened 2 degrees and closed 1 degree for the 8.5 degrees of loft club. ZL clubs with greater loft all have measurements of 1 degree open and 2 degrees closed. The neutral setting is actually .5 degree open for the 8.5 degrees of loft club and .5 degree closed for the rest.