The shaft is roughly in diameter near the grip and from in length. Shafts weigh from , depending on the material and length. Shafts are quantified in a number of different ways. The most common is the shaft flex. Simply, the shaft flex is the amount that the shaft will bend when placed under a load. A stiffer shaft will not flex as much, which requires more power to flex and "whip" through the ball properly (which results in higher club speed at impact for more distance), while a more flexible shaft will whip with less power required for better distance on slower swings, but may torque and over-flex if swung with too much power causing the head not to be square at impact, resulting in lower accuracy. Most shaft makers offer a variety of flexes. The most common are: L/W (Lady/Women's), A/I (Soft Regular, Intermediate or Senior), R (Regular), S (Stiff), and X (Tour Stiff, Extra Stiff or Strong). A regular flex shaft is generally appropriate for those with an average head speed (), while an A-Flex (or senior shaft) is for players with a slower swing speed (), and the stiffer shafts, such as S-Flex and X-Flex (Stiff and Extra-Stiff shafts) are reserved only for those players with an above average swinging speed, usually above . Some companies also offer a "stiff-regular" or "firm" flex for players whose club speed falls in the upper range of a Regular shaft (), allowing golfers and club makers to fine-tune the flex for a stronger amateur-level player. At impact, the club head can twist as a result of torque applied to the shaft, reducing accuracy as the face of the club is not square to the player's stance. The ability of a shaft to twist along its length due to this torque is fundamentally a function of the flex of the shaft itself; a stiffer shaft will also torque less. To counter torque in more flexible shafts, club makers design the shafts with varying degrees of torque through their length, particularly along the thinnest part of the shaft where it joins with the club head. This results in a point at which the shaft is most flexible, called the "kick point"; above that point the increasing diameter of the shaft makes it more rigid, while below that point the shaft is reinforced internally to reduce torquing of the club head. Shafts