A 'bit' is the metal mouthpiece that is attached to a horse's reins, allowing the rider to control the animal. The Japanese are believed to have used horses in battle probably as early as the beginning of the Kofun period (late fourth century). There are surviving haniwa showing mounted warriors. The practice seems to have come from Korea. The close connections between Japan and Korea brought many similarities of culture. This is one of two sets of bits obtained by William Gowland from a tomb at Rokuya in Tamba Province. They show advanced skill in the forging of iron and working of decorative metals. The end pieces have gilt copper overlay using the mercury amalgam method. The rivet heads are dressed with sheet-silver.