Polo taken. The official set of rules and rules interpretations are reviewed and published annually by each country's polo association. Most of the smaller associations follow the rules of the Hurlingham Polo Association, the national governing body of the sport of polo in the United Kingdom, and the United States Polo Association. Outdoor or field polo consists of four to eight 7-minute chukkas, between or during which players change mounts. At the end of each 7 minute chukka, play continues for an additional 30 seconds or until a stoppage in play, whichever comes first. There is a four-minute interval between chukkas
Polo shields. A shirt or jersey is required that distinguishes the player's team, and is not black and white stripes like an umpire shirt. White polo pants or trousers are worn during official play. Polo gloves are commonly worn to protect from working the reins and mallet. Not permitted is any equipment that may harm horses, like certain spurs or whips. The modern outdoor polo ball is made of a high-impact plastic. Historically they have been made of bamboo, leather covered cork, hard rubber, and for many years willow root. Originally the British used a white painted leather covered cricket ball.