In-line skates (often called Rollerblades after the popular trade name) are a type of roller skate used for inline skating. Unlike quad skates, which have two front and two rear wheels, inline skates have two, three, four or five wheels arranged in a single line. Some in-line skates, especially those for recreation, have a "stop" or "brake" which is used to slow down while skating; most have a heel stop rather than the toe stop, particularly indispensable for in-line figure skating.