This image of a skimmer has been issued by the PSNI to let the public see exactly what it looks like.
In a post on Facebook, PSNI Cookstown say: "This is the skimmer that was fitted to the self service petrol pump in Cookstown that we posted about on Friday.
"Take a good look at it and make sure you know what you are looking for.
"Make sure your mates know what to look for as well.
"The red box around the tip is to show all that was visible."
The post adds: "If you find one of these, DO NOT REMOVE IT. Leave it where it is and call us.
"Spread the word."