Casters are a type of furniture accessory that allow for easy movement of furniture. They are typically made of metal or plastic and have a wheel attached to the bottom. They are often used on chairs, tables, and other furniture pieces to make them easier to move around. Slingsers are a type of caster that has a spring-loaded mechanism that allows the caster to be locked in place when not in use. This makes them ideal for furniture that needs to be moved frequently, as they can be easily locked and unlocked.