A great price for the MC11 adapter that allows you to use Canon lenses on Sony E-mount bodies (though focusing will be rubbish on A7, A7R, and A6000, probably also on A7S) but should be great on A7R II, A6300, A6500, and not too bad on A7 II. It is intended for Sigma EF lenses, but have seen reviews on Youtube showing it works great with Canon lenses too.
Considering the cost of the Metabones MkIV adapter this competes with this is a great price. I'd suggest this is also a better option than using Sigma lenses with the Sony LA-EA3 adapter as the Sigma adapter gives you native focusing modes, and Canon fit lenses will probably have a higher resale value if you come to want to sell them on.
The Sigma mount version is also the same price, but that limits you to the Sigma specific lenses, and the resale value of those lenses would be rubbish so I wouldn't bother.
This will probably also combine with the £50 cashback on £150 spend with Amex card.