Carbon Innovations carbon fiber equipment spikes.  Developed by Silicon Valley engineers who are also audiophiles.  Made in USA.  I bought up the remaining stock (limited) from the local company here previously who specialized in carbon fiber technology accessories.  Sold for much more originally.

Set of 3 carbon spikes per box.  They can be used for equipment up to 30 pounds, typically your preamp, DAC, streamer, CD player et al.  Experiment by placing it upright or inverted.  Includes a set of screws if you want to permanently mount it to the bottom chassis of your equipment (especially if you are building your own).  Each spike measures 1.5" in diameter and .75" high.