Impossible to know if you don't have the exact spec.

The deductions for the Arbeitnehmer should be:

AHV/ALV - 5.05%
ALV - 1%
NBU if applicable - approx. 1-2%
KKT if applicable - approx 1-2%
BVG if applicable - depending on your age but anything between 3% and 10%
Quellensteuer - % according to your salary

So you need to go back to them and ask what exactly is included in the 11.05%.

The quellensteuertables you can find on the net so you can check that one yourself.