A combination spring tension rod and mounting bracket assembly easily mounts within a window opening. A pair of mounting bracket devices are mounted to opposite ends of the spring tension rod. The spring tension rod is compressed and positioned such that bearing surface portions of the bracket devices extend into the window opening. The spring tension rod is then released and forces the bearing surfaces to bear against opposed and facing surfaces of the window opening when installed. The spring force of the spring tension rod retains the rod and brackets in the installed position.