What players can be Co-star paired with a Strato player?

Only M-Class players (KPLAYER-M300, KPLAYER-M500, KPLAYER-M700, Cinema One 2nd Gen or Kaleidescape Alto) can be paired with a Strato player. 

NOTE: A Strato V in standalone mode does not support Co-Star pairing. Strato V supports Co-Star pairing only when grouped with a Terra or Terra Prime server. Only system-level pairing with an M-Class Premiere player is supported. Player-pairing with an Alto is not supported.

Co-Star pairing is not supported on Strato E or Strato M.

Please check the below link for further system pairing information. 

https://www.kaleidescape.com/support/article/Kaleidescape-Co-Star-Installation-Guide