Abstract: The present disclosure relates to a retention device for displaying protective cases, particularly for collectible trading cards. The device comprises a body with a back plate that defines a flat vertical surface. This body features a first top end and an opposing bottom end, each equipped with retaining structures. The first top end includes at least one first retaining structure designed to support the top edge of a protective case when installed flush against the back plate. The opposing bottom end similarly includes at least one second retaining structure for supporting the bottom edge of the installed protective case. Additionally, the back plate incorporates at least one cavity intended to house a magnetic element. This magnetic element is strategically positioned to align with a corresponding metallic or magnetic element of the protective case, facilitating a secure and aesthetically pleasing display.