Provided is a racket including a head portion connected to a handle portion. The head portion includes a beam including string holes and at least one string looped through the string holes, the racket further includes at least one tensioning device rotatably arranged on a support surface on the exterior surface of the beam relative to which it can be rotated between a first and a second position. The tensioning device includes a through hole arranged parallel and offset to the rotation axis and extending through the tensioning device. The at least one string is looped from a first string hole through the through hole to a second string hole, so that the tension of the at least one string can be varied by rotation of the tensioning device between the first and second position, and where the outer circumference of the tensioning device further includes a mating surface for mating with the support surface. The mating surface extends from a first mating patch which contacts the support surface in the first position to a second mating patch which contacts the support surface in the second position and where the cross section of the mating surface perpendicular to the rotation axis has an arched shape.