Tesco sells bondage gear? Oh, no, sorry, it's a chocolate bar!!!! (Where do they get these names!)
1 syn per 20 calories. Trouble is, there are different calorie values given online. I have seen 100 and 116 per bar. 100 would be 5 syns, 116 almost 6 syns. You would need to check the information on the package, as they seem to come in different sizes.