Cage with floating heat sink for use with a parallel optical communications device

A floating heat sink device 20 is provided that attaches to a cage 10 in a floating configuration that enables the heat sink device to move, or "float", as the parallel optical conmiunications device 71 secured to the cage moves relative to the cage. a cage housing; a heat sink having a surface 30b disposed in an opening (11) of the cage housing; and a spring clip 50 in contact with the heat sink for retaining the heat sink in contact against the cage housing while allowing the heat sink to move relative to the cage housing. Because the heat sink device floats with movement of the device, it maintains continuous contact with at least one surface of the heat sink device (20) at all times. Ensuring that these surfaces are maintained in continuous contact at all times ensures that heat produced by the parallel optical communications device will be transferred into and absorbed by the floating heat sink device.