This invention comprises a self-centering mechanism for retaining an object, a clamping device for retaining an electronic device or an electronic device in a case, and means to integrate the devices in an adapter form. The structure of the self-centering mechanism allows for a compact device that is capable of fitting a wide range of differently sized and shaped objects. The clamping device allows for means to retain an electronic device or an electronic device in a case that is capable of fitting a wide range of differently sized and shaped electronic device. The self-centering mechanism and clamping device can also be integrated into the form of an adapter for various applications.

A clamper includes a base, a movable element, a sliding element, a connecting bar, a clamping element and a first elastic element. The movable element is movable in a first direction relative to the base. The sliding element is movable in a second direction relative to the base. The connecting bar connects the movable element and the sliding element. The clamping element sets on the sliding element. The first elastic element includes a terminal setting on the sliding element.