Exposure ControlExposure Control type: Stroboscopic flash, manual flashGuide number: 40 (at 50mm focal length, ISO 100 in meters)Effective flash range: 0.7-29m (with EF 50mm F/1.4 , ISO 100)Flash exposure compensation: Manual, ±0.3 stops in 1/3 or 1/2-stop incrementsFlash exposure confirmation: flash exposure confirmation lamp lights Flash RecyclingRecycling time: normal flash 3.0 sec (with size-AA alkaline batteries)Flash-ready indicator: red pilot lamp lightsWireless FlashTransmission method: Optical pulseSlave Flash modes: S1 S2External power: compact battery pack CP-E4Transmission range (Approx):Reception angle: ±40°horizontal, ±30°verticalDimensions (W x H x D): 72 x 122 x101 mmWeight: 320g (excluding batteries) Suitable for:Work with all flash units using universal hot shoe like Canon, Nikon, Sigma, Olympus, Pentax (except Minolta/for Sony/Konica) Package including:JY-620 Flash x1Flash pouch x1Flash stand x1Retail packaging