Outdoor Unit Indoor Unit   BTU Option 
   CU-3S27MKZ      CS-S9PKZW    9K BTU
CU-3S27MKZ   CS-S12PKZW   12K BTU
CU-3S27MKZ CS-S18PKZW  18K BTU


Please note that warranty coverage is only limited to the following combination:


            
Panasonic System 1   Panasonic System 2
(4 Ticks)
 
Panasonic System 3
(3 Ticks)
  

Panasonic System 4
(2 Ticks)
 Panasonic System 2 
(2 Ticks)