Just picked up one of these from the Orpington Tesco. Apparently the last one, but I think this is national. The advantages of this model over the PC version posted previously at £75 are:
This is a bit cheaper.
It comes with a 3 year warranty rather than 2 year.
It appears to contain a WD Red drive rather than a Green (hence the difference in warranty).
Don't worry about it being for a Mac, the drive can easily be reformatted to work with Windows.https://www.wdc.com/en-gb/products/external-storage/my-book-for-mac.html#WDBYCC0030HBK-EESN