As far as I can see, one can order one of the:
- 494 (front)
- 4HA (front and rear)
- 4HB (front with armrests and steering wheel)
Or you can order
- 4HA and 4HB together (everything heated)
In this case, price of 4HA is reduced by the price of 494. At least in my country.
Honestly, as others pointed out, this is unnecessarily confusing
