Two spring compressors, normally used for compressing car wheel strut springs when replacing the struts.
Since I had just replaced a set of struts the clamps were hanging around when I perceived this use for them.
Two lengths of chain wrapped around the post and engaging the single hook on each of the compressors, the douple hook of the closest one engages the 2x4 top plate, the less closer compressor upper double hool engages the 2x6 cross beam and is mostly obscured.