From the specs I have consulted (CNET,...), I would say that this memory is compatible. In general, iMacs are more restrictive than PCs.
So order them and try them out in the Travelmate; if they don't fit, as long as the original packaging hasn't been destroyed, Digitec should take them back (ask them first ;-)). Personally, I don't see any risk of incompatibility.
Note that DDR3 _must_ be in pairs.

Hello

In theory, it is compatible (according to the characteristics of your machine)
https://www.manualslib.com/manual...

But, in the real case, it is not 100% guaranteed!
you should check the ACER website for more info

/Sam