These are Stabilizers for the anti-vibration feet sold in the Bambu Store. Anybody who has installed these feet may have found that due to their height, the tend to buckle and pop out if you try to move the printer. This has only been tested with a P1S but should work with other models.

These stabilizers press onto the boss on the bottom of the printer and act as a guide to keep the feet from kicking out or falling off.

Just press the foot into the well

And then press on the stabilizer. They are a tight fit, giving them a little twist while pressing helps. Make sure they are flush against the base. Make sure the end with the lip is facing the top of the printer.

There are two different stabilizers.  One for the official Bambu feet from the store and one for the aftermarket feet like you find on Amazon.  

The taller stabilizer goes with the shorter Amazon feet and the shorter stabilizer goes with the taller Bambu feet.  This seems backwards but the Bambu feet crush further so the stabilizer needs to be shorter

Once properly installed they will not restrict the movement of the anti-vibration foot yet they will stop the feet from tipping out if you need to slide the printer around

Please let me know in the comments if this is useful or if you have any suggestions.