Abstract: An anti-theft device for securing an article of merchandise against unauthorized removal from a display counter. The anti-theft device includes a plurality of arms slidingly disposed within the housing. Grips are disposed on proximal ends of the arms and are configured to receive and secure edges of an article of merchandise. A locking mechanism is disposed within the housing of the anti-theft device. The locking mechanism involves an actuator that presses a locking component to engage at least one of the arms. The arms have a first set of teeth disposed thereon, such that, when the locking component engages at least one of the arms, the first set of teeth interlocks with a second set of teeth. The arms cannot slide relative to the housing while the first set of teeth and the second set of teeth remain interlocked.

Abstract: A tennis-stroke trainer device is an apparatus that allows a user to perform various tennis strokes repetitively. The apparatus includes a frame, a training ball, a pair of length-adjustable fasteners, and an elastic cord. The frame offset and rotates the training ball around a post. The post is preferably a tennis post. The frame includes a U-shaped bracket, a cantilever arm, a counterfort arm, and a hook. The U-shaped bracket offsets and mounts both the cantilever arm and the counterfort arm with the post. The hook stretches the elastic cord along the cantilever arm. The training ball is preferably a large foam ball and serves as a target for the user. The pair of length-adjustable fasteners mounts the U-shaped bracket with the desired post. The elastic cord retracts the cantilever arm and the counterfort arm, and consequently the training ball after the training ball has been hit by the user.

Abstract: A tennis-stroke trainer device is an apparatus that allows a user to perform various tennis strokes repetitively. The apparatus includes a frame, a training ball, a pair of length-adjustable fasteners, and an elastic cord. The frame offset and rotates the training ball around a post. The post is preferably a tennis post. The frame includes a U-shaped bracket, a cantilever arm, a counterfort arm, and a hook. The U-shaped bracket offsets and mounts both the cantilever arm and the counterfort arm with the post. The hook stretches the elastic cord along the cantilever arm. The training ball is preferably a large foam ball and serves as a target for the user. The pair of length-adjustable fasteners mounts the U-shaped bracket with the desired post. The elastic cord retracts the cantilever arm and the counterfort arm, and consequently the training ball after the training ball has been hit by the user.