The Ikelite Digital SubStrobe DS-51 was created specifically for use with digital cameras because of their use of preflash metering, but it is completely compatible with all film cameras and film camera housings. The DS-51 offers 50 watt-seconds of power in a compact size with coverage adequate for lenses as wide as 28mm, or add the included diffuser for wider coverage and softer lighting.
Features: 50 Watt/seconds power with a guide #28 (underwater at ISO 100) Operates TTL when connected to some Ikelite housings or manual exposure mode with six manual power settings in half f-stop increments 70° angle of coverage, 80° with diffuser Recycle time of 3.5 seconds (Full power) Up to 200 flashes with full power batteries 5700° Kelvin color temperature The Pop Bead Flex Arm allows for perfect placement and is easy to adjust The included Flex Mount Ball Extended Stem allows you to mount the strobe onto an Ikelite Quick Release Handle
Full Manufacturer's Specs can be found HERE
Requires 4 AA batteries.
Manual can be found HERE