They are used for the 4 outer chakras in the place of using 2 forks from the Chakra Set and with the Solfeggio set.

The complete set: Michael, Sandalphon, Metatron, and Shekinah forks. Also included are instructions for use and a velvet pouch for their easy storage and carrying.
 
Descriptions of each fork (to follow) on the Descriptions of the Archangel fork set page