larger diamond set in the middle and smaller diamonds on the side fit under this category. Three-stone diamond engagement rings, sometimes called trinity rings or trilogy rings, are rings with three matching diamonds set horizontally in a row with the bigger stone placed in the center. The three diamonds on the ring are typically said to represent the couple's past, present, and future, but other people give religious significance to the arrangement. A wedding set, or bridal set, includes an engagement ring and a wedding band that matches and can be bought as a set. In some cases, the wedding ring looks incomplete; it is only when the two halves, engagement and wedding, are assembled that the ring looks whole. In other cases, a wedding set consists of two rings that match stylistically and are worn stacked, although either piece would look appropriate as a separate ring. Although the wedding band is not to be worn until the wedding day, the two rings are usually sold together as a wedding set. After the wedding, the bride may choose to have the two pieces welded together, to increase convenience and reduce the likelihood of losing one of the rings. A trio ring set includes a women's engagement ring, a women's wedding band, and a men's wedding band. These sets often have matching rings and are lower in price. In Nordic countries, engagement rings are worn by both men and women. Traditionally they are plain gold bands, although more ornate designs and other materials are gaining popularity. The engagement rings resemble the wedding bands sold in the United States, whereas women's wedding rings may resemble US engagement rings. In North America and the United Kingdom, it is customarily worn on the left hand ring finger. Similar traditions purportedly date to classical times, dating back from an early usage reportedly referring to the fourth finger of the left hand as containing the vena amoris or "vein of love". This custom may have its origins in an ancient Egyptian myth that the finger contained a vein leading directly to the heart, or it may simply be because the heart lies slightly to the left side of the body. In Germany the ring is worn on the left hand while engaged, but moved to the right hand when married. In Poland and Turkey, the engagement ring and wedding band are traditionally worn on the right