Drivers should be on the lookout for credit card skimming devices at gas stations where they pay at the pump, police say.

Crime Stoppers and the Calgary Police Service economic crime unit teamed up for a re-enactment on Tuesday to show people how easily the devices are to attach to a pump — and how to spot them.

pay at pump no skimmer

A pay-at-the-pump terminal as it normally appears. (CBC)

skimming device added

A pay-at-the-pump terminal with a credit card skimming device fitted over top of the real one. (CBC)

"Give the skimming device on the outside of the gas pump a jiggle. If it seems like it's too new or too old or out of place in comparison to the pump, it probably is," said Staff Sgt. Kristie Verheul.

If the card goes in too far, or it's difficult to insert the card, there could be a skimming device attached to the machine.

It only takes culprits a few seconds to attach a credit card skimming device.

They then leave it for a few days, retrieve it, and download credit card information onto counterfeit cards, police say.

Police say there has been an increase in this type of crime in Calgary over the last couple of months.