Hartleys Low Calorie Apple and Pear Jelly

Can someone just check this for me, I put it though the syn calculator online and it comes up free, just want to double check as all the rest (strawberry/kiwi, cranberry/raspberry, blueberry/blackcurrant, apple/watermelon, mango/passionfruit) are 0.5 syns.

per 100g 4 calories, 0 protein, 1 carb, 0 fat. 175g pot.

is free right? If so i'll be getting some more in

1 syn for every 20 calories so it would be ½ syn

Yeah thats what I thought, calculator keeps telling me its free though, even put in the other jellies and they all came up 0.5, but this one nope keeps giving me free.