Here is some info that Futaba wanted me to share on the 4PL.
The 4PL will work with the following receivers.
R603GF (In FHSS Mode), R2004GF (In FHSS Mode), R2104GF (In FHSS & SFHSS Modes).
All three receivers above has a voltage range of 4.8 to 7.4V's.
J
Linked this post in the first post for future reference "thumbsup"