striking face, except that a putter may have two such faces if their characteristics are the same, and they are opposite each other. Page 127 of the USGA rules of golf states: A putter is a club with a loft not exceeding ten degrees designed primarily for use on the putting green. Therefore, any double sided club with a loft greater than 10 degrees is not legal. Ferrule The trim ring, usually black (It may have additional trim colors), that is found directly on top of the hosel on many woods and irons. The ferrule is mostly decorative, creating a continuous line between the shaft and the wider hosel, but in some cases it can form part of the securing mechanism between hosel and shaft. Ferrules of differing weights can fine-tune the center of mass of the overall club head, but for these minute adjustments, screw-in weighted inserts at specific points on the club head are usually used instead. Club sets The rules of golf limit each player to a maximum of 14 clubs in their bag. Strict rules prohibit sharing of clubs between players that each have their own set (if two players share clubs, they may not have more than 14 clubs combined), and while occasional lending of a club to a player is generally overlooked, habitual borrowing of other players' clubs or the sharing of a single bag of clubs slows play considerably when both players need the same club. The most common set of men's clubs is: A driver, usually numbered a 1-wood regardless of actual loft, which varies from 8° up to 13° A fairway wood, typically numbered a 3-wood and lofted about 15° (though 2- and 4-woods are sometimes seen) A matched set of 7 numbered irons from 3 through 9, plus a pitching wedge or "10-iron" A sand wedge A putter The above set is only 12 clubs; these (or equivalent hybrid substitutes) are found in virtually every golf bag. To this, players typically add two of the following: Another fairway wood, often a 5-wood lofted around 18°, to allow other options besides long irons in the 180–250 yard range, A hybrid, typically lofted for similar distance as a 3- or 4-iron and usually replacing instead of supplementing those clubs in the bag, and/or An additional wedge, usually either: A gap wedge lofted near 52° to fit between the modern pitching and sand