The Pocket Wizard AC5 RF SoftShield is used for the enhancement of the PocketWizard FlexTT5 Radio Transceiver.The FlexTT5 Radio Transceiver enhances the Pocket Wizard AC5 RF SoftShield when used with Canon 430EX, 580EX, and 580EXII flash unitsOne of the vital camera lighting accessories, this soft shield helps in reducing the radio frequency of the Canon flash units , thus segregating them from FlexTT5 antenna and circuitryThe Pocket Wizard AC5 RF SoftShield thus improves flash operation