Yongnuo YNE3-RX receiver is compatible with the Canon RT radio system, so non RT speedlite like canon 580EX II or YongNuo YN-568EXII can now act as RT compatible slave flashes when using the canon ST-E3-RT/YN-E3-RT,or YN600EX-RT or 600EX-RT as transmitter. Features: Supports flash mode: E TTL, M, MULTI Supports remote shutter release function, test flash Supports PC output interface Supports USB firmware upgrade Supports single contact triggering Supports single contact flash triggering LCD Display Specifications: Type: Wireless flash receiver Distance:100m Channel: AUTO, Ch. 1-15 Groups: 5 groups(A/B/C/D/E) Frequency: 2405-2475MHz Wireless ID: 0000-9999 USB firmware upgrade: Support Compatible battery: 2 x AA (support 1.2V rechargeable batteries) (not included) Working time: 24 hours Size: 92.5*50*37mm Weight: 70g The compatible transmitter (master unit): YN-E3-RT/YN600EX-RT/ST-E3-RT/600EX-RT Parts of the compatible E-TTL flash list: Canon 600EX( RT) /580EX II /430EX II Yongnuo YN568EX(II)/ YN565C/YN468C(II) /YN467C(II) /YN465C Package Includes: 1 x Yongnuo YNE3-RX E-TTL Wireless Flash Receiver 1 x Sync cable PC-635 (PC-sync - Jack 6.3 mm) 1 x Adapter Jack 6.3 mm Jack 3.5 mm 1 x User manual