The Studio PRO title macro ring flash light for canon is an easy to use compact flash for close-up macro photographers with through the lens exposure metering (title). This ring flash puts the flash right were you need it for close up, detailed, macro photography images. The large sized lcd display is easy to read and use. It attaches to many common lens sizes with the included lens adapter rings. Technical specs guide number (gn) : 14 @ is 100 transmission range: 20cm-5 meters flash coverage: approx.80 Degrees up and down button and 80 degrees left and right firing configuration: two flash tubes can be fired together or singly exposure control type: title, manual flash, multi-flash flash control: 1: 8-1 :1 or 1 : 1-8: 1 in 1/2-stop increments color temperature: 5500k flash time: 1/200s-1/20000s flash amount: 100-1500 flashes external interface: hot shoe, pc sync port, external charging port flash ready indication: approx.2.9S power source: 4 x aa alkaline batteries or aa ni-mh batteries extra function: power saving mode, overheat protection mode control unit (speed light) size: 5.6″ X 3″ x 2.5″ Flash unit (ring flash) size: 5″ x 5″ x 1″ weight: 1 lbs. Dimensions (box): 8″ x 6.5″ X 5″ weight (box): 2 lbs.