Abstract: The assembly includes a watch, a watchband, a tracking device and a flexible retaining part formed to engage the watchband and to retain the watch and the tracking device. The part has a cylindrical shape wall with an open top edge spaced from an inwardly extending collar to define a recess to receive the tracking device. Frist and second arcuate wall extensions are connected by a member and define aligned openings through which the tracking device can be inserted into the retaining part, and which are adapted to receive the watchband. When the watch is situated in the top of the part, the tracking device is situated in the collar in the interior surface of the retaining part, and the watchband is inserted through the align openings, the tracking device is securely retained between the watchband and the watch. The watchband may be a “slap” watchband.