A wrist-worn physical activity measurement apparatus is disclosed. The apparatus (100) includes a bracelet (102) comprising a plurality of links (104), each link being formed at one side to comprise a part and at the opposite side a counterpart interlocking with a part of an adjacent link, and a flexible casing (106) encasing the plurality of the links. The apparatus (100) is attachable around a curvature of a wrist of a user such that the links and the adjacent links are pivotably lockable in relation to each other in order to wrap and lock around the wrist.
