Use code JEWSON-TEN to get £10 off.https://www.jewsontools.co.uk/offer
Actually stumbled across this while reading another thread on here http://www.hotukdeals.com/deals/nest-protect-gen-2-bundle-159-currys-2517413
So user llywmog should get all the credit but he/she doesn't seem to think its that good a deal.
That might be the case but I would have spent full price £89 on it if I hadn't seen his/her comment so I thought I'd make it a bit more visible to maybe help other people.
Vote cold if you want, not doing this for any kind of "cred" just trying to be helpful.