Support and dampener for Folgertech Kossel, or any printer with 2020 aluminum beams. For a delta printer make six. You can do three, but you have to be careful not to put the whole weight of the printer on only one while setting it up because it will deform (I accidentally found this out first hand) . Basically distribute the weight evenly.The pip in the center fits into the groove of 2020.

The shape allows for relatively easy printing while being both strong and flexible enough to dampen vibration of the system. My printer used to make all kinds of noise when printing, now all I hear is the fan cooling the heatsink.

Edit:
Added STEP and STL for an update with a 3mm and 4mm hole for securing it