Plastic blister packs and clamshells are commonly sealed by the ultrasonic welding technique. There they fished, swam and collected oysters and clamshells used to make wampum. Some typical examples of moving target setups are swingers, bobbers, clamshells, movers, and drop turners. The term now refers to both those and the purple beads from quahog clamshells. Clamshells can use a variety of means of closing or sealing. The black stones are made of slate, while the white stones are made from clamshells. There was also a large amount of ivory and clamshells. A further seven phones, mainly clamshells, came in 2005. The picture of the aircraft shows the clamshells deployed directing thrust forwards. Most often, clamshells can only accommodate a single occupant. As clamshells disappeared from the market, the terms again became disambiguated.