Squash tennis is played in various four-walled courts. The front wall (against which the ball is served) features a telltale (usually clad in tin) at the bottom couple feet from the floor, a service line about 6 feet (1.8 m) from the floor, and an out-of-bounds line around 16 feet (4.9 m) from the floor. The back wall out line is 4.5 feet (1.4 m) from the floor. There are two required lines on the floor: a service line about 10 feet (3.0 m) from the back wall, and a center court line running at least from the front wall to the service line. Unlike a squash racquets court, there are no service boxes.