US Patent 7578065 Devices for determining the string tension of racket strings

Devices for determining the string tension of racket strings are provided. In some embodiments, devices for determining the string tension of racket strings comprise: a body having a front surface indicating different combinations of player and racket characteristics, windows corresponding to certain types of rackets, and an axis perpendicular to the front surface; and a rotary disc which is rotatably situated on the axis behind the front surface and which has numbers indicated thereon representing racket string tension values that can be viewed through the windows for the different combinations of player and racket characteristics.