YONGNUO E-TTL YNE3-RX Wireless Remote Flash Receiver for YN-E3-RT/ YN600EX-RT/ST-E3- RT/ 600EX-RT Supports single contact triggering Supports single contact flash triggering Supports PC output interface,Supports USB firmware upgrade Supports flash mode: ETTL,M,MULTI Supports remote shutter release function,test flash