Abstract: Embodiments of the present disclosure can comprise systems and devices for improving a player's tennis swing timing. In some embodiment, the systems and devices can comprise a first band having a first sleeve affixed thereto and a second band having a second sleeve affixed thereto. An inner tubing can extend substantially between the first end of the first sleeve and the first end of the second sleeve. Additionally, the first sleeve can house a first magnetic component and the second sleeve can oppose the first sleeve and house a second magnetic component. The first and second magnetic components can be configured to transition the first and second sleeves from an unconnected state, in which at least a portion of the inner tubing is disposed between the first sleeve and the second sleeve, to a connected state.