The spring support is a good price performance ratio. Before mounting the adjusting rausdrehen on the lower side and the items and lock something with technical Vaseline or other fat grease then reassemble. (Therefore there is no noise during compression!) The seatpost has to provide a minimum installation height of just 65mm (bottom caliper bracket) deeper is not possible. For persons under 80kg I recommend the adjustment by half the threads out and turn with a drop of glue, varnish or Loctite rotate anti- secure.
I would buy the part immediately works sufficiently well. (My weight 94kg)