The personal information you carry in your wallet isn’t safe at places like sporting events, theme parks, concerts or even the grocery store.

At one time, gas station skimmers were the biggest threat to unsuspecting consumers. Now, high-tech criminals are snatching personal information from people wirelessly in crowded places using inexpensive RFID readers.

Criminals hide the devices in a bag or backpack, walk by people at a public place like a shopping mall, and are able to silently retrieve numbers off credit/debit cards in a matter of seconds, without the victim knowing.

Security experts have dubbed the new form of pickpocketing “crowd hacking” and say information can be stolen up to 25 feet away from the RFID reader.

Florida entrepreneur Chris Gilpin has created a simple piece of technology to help combat the problem. SignalVault looks similar to a standard credit card, but it’s a little thicker and blocks the RFID readers from picking up any information by utilizing what Gilpin calls “E-Field Technology.”

While SignalVault protectors add a little extra weight to your wallet, it’s well worth it to keep your personal information secure.

A SignalVault one-pack sells for $14.95, doesn’t require batteries or charging, and lasts up to five years. Gilpin will pitch SignalVault to investors on the season premiere of ABC’s Shark Tank this Friday, September 25.