A power coupler has been designed and built at Argonne National Laboratory for use with the Project X Injector Experiment (PXIE) 162.5 MHz superconducting (SC) half-wave cavities. The 50 Ohm coaxial capacitive couplers will be used to operate 8 cavities CW with up to 10 kW of forward power under any condition for the reflected power. A key feature is a moveable copper plated stainless steel bellows. The bellows permits up to 3 cm of axial stroke and adjustment of Qext by two orders of magnitude in the range of 10 -5 - 10 -7 . The mechanical and vacuum design includes two ceramic windows, one at room temperature and another at 70 Kelvin. The two window design permits a compact, low particulate assembly inside the clean room. We present other design features including thermal intercepts to provide a large margin for RF heating and a mechanical guide assembly for low-friction motion while cold and under vacuum.