The Bo Pep finger rest snaps onto the flute body, building out the tube to provide a support for the left-index finger. This allows the left-hand grip to open and thus reduce tension and improve balance.
The rest may be adjusted to suit individuals and is especially useful to those with larger hands. It is sold with a draw-string bag that can be tied to the instrument case for convenient transport.
Manufacturer’s website: conn-selmer.eu