Canon Speedlite 90EX (6825B002) Flash Series: Speedlite Specifications: Number of Flashes: Approx. more than 100 times Custom Functions: C.Fn-01: Auto power off (ON/OFF) Compatibility: Type-A EOS Cameras (E TTL II/E TTL Autoflash) Guide Number: Approximately 30 ft./9m at ISO 100 AF-assist Beam: System: Intermittent flash firing system Effective Range (Approx.): At Center: 9.2 ft. / 2.8m Periphery: 8.2 ft. / 2.5 m Recycling Time: Normal flash: Approx. 0.1 - 5.5 sec./ Lamp lights (with size-AAA/LR03 alkaline batteries) Power Source: Two AAA-size/LR03 alkaline (size AAA/LR6 Ni-MH or lithium batteries also possible) Dimensions: Approx. 1.7 (W) x 2.0 (H) x 2.6 (D)