Which product is the best? Ans. PhotoBlockerTM spray is the best product we carry. FOX NEWS investigative news reporters and the Denver Police Department tested PhotoBlockerTM spray with actual photo-radar equipment. They found it to be “surprisingly effective.” The spray is invisible from a distance. No one will know that you have it on. ONE CAN WILL PROTECT UP TO 4 PLATES. ADDITIONALLY, ONE APPLICATION IS GOOD FOR LIFE. IT WILL NEVER WASH OFF!