Camera Flash TT520 Summary:Camera flash TT520 Guide number:GN33 for TT520,GN38 for TT560 Vertical rotation angle:0~90 Horizontal rotation angle:0~270 Consistent Flash Output:1/128,1/64,1/32,1/16,1/8,1/4,1/2,1/1 Recycle time:approx 0.1~5s (AA alkaline cell used) Lighting times:100 to 1500 times(AA alkaline cell used) Equipped with a pull out reflector/diffuser Batteries (Optional):4 AA Alkaline/4AA Rechargeable Ni-MH An optical receiver hosted inside makes the flash an optical slave if needed. Suitable for all DSLR Camera with standard hot shoe,such as Nikon,Canon,Pentax,Olympus,and so on.