These coins were featured on Fake Britain in November 2015 as the best counterfeits ever seen, due to their ability to fool coin validators 100% of the time. Whoever is responsible for making these has tried many different alloy mix configurations to get this right, as can be seen HERE and can also be seen by the different central disc colours too! The rotation of these coins is often a giveaway, as is the portrait and quality of the 'join' between the two metals which often bleed into eachother. Watch the episode on YOUTUBE