It never fails that these issues generate lots of confusion, even amongst some seasoned travelers.
RFID is a completely separate payment system that works without direct contact to the card reader. As a few have noted, transit cards, employee ID cards, passports and some credit cards use this system. But is has NOTHING to do with the much-talked-about EMV chip credit cards and the one that Brenda mentions in her OP. A chip and PIN or chip and signature card must be inserted into a reader so it can make contact with the chip itself.
So do you need RFID protection?
Do you have a credit card with RFID technology? It'll show the little Wi-Fi symbol on the card. If not, you are wasting your money completely. The other cards mentioned that use RFID are useless to thieves even if they could steal your data, including your passport.
If you do happen to have an RFID credit card, know that stealing the data is extremely difficult and rare. Yes the companies that sell sleeves and blockers show someone holding a reader next to your ass, but the equipment has to be extremely sophisticated and the criminal enterprise highly resourceful to actually break the encryption and make use of the data. Your average thief is neither of those. Know that people the world over have RFID cards and there is no huge security fraud with them. Your old fashioned magnetic strip credit card is a multitude times more vulnerable to fraud than an RFID card. Your brand new chip and signature card is far more susceptible to fraud than an RFID card will be. So ask yourself is the cost to protect yourself from something with such little risk is really worth it?