NEO: two advanced engine – CFM International’s LEAP-1A and Pratt & Whitney’s PurePower with a fuel improvements of 20%, and a new Sharklets
A321 ACF: Aircraft Cabin Flex – the A321neo’s with max seating capacity of 244. and a new cabin door 
A321 LR   extended range to 4,000 nm with 206 passengers by three Additional Centre Tanks (ACTs).
A321 XLR:  extended range up to 4,700nm with a permanent Rear Centre Tank  and an optional forward ACT.