A compact unit that converts the camera's TTL signal to a light signal. The converter can be mounted on the camera's accessory shoe and can be connected to (a) SEA&SEA strobe(s) with Fiber-Optic Cable(s) (*). TTL and manual modes can be switched by pushing the mode switch on the housing.
* SEA&SEA's Fiber-Optic Cable II must be used with an Optical YS Converter.

Advantages of using the Optical YS Converter and not using the camera's built-in flash
- Risk of water-ingress and flooding via the strobe bulkhead is eliminated.
-The camera's battery will last longer.
-External strobes will fire in accordance with their quickest recycle time.
-No inner reflections from camera's built-in flash.
-Compared with slave TTL, the Optical YS Converter achieves far greater accuracy in TTL exposure/output.
-Optical YS Converter is compatible with SLR cameras that do not have a built-in flash.

[Controls] Power ON/Power OFF/TTL mode (indicated by blue lamp)/Manual mode (indicated by green lamp)
* Remaining battery level is indicated by flashing LED lamp.
[Auto Power Off] The converter will automatically power off if the shutter lever or the mode switch is not activated for more than one hour.
* The converter can be re-activated by pressing the mode switch.
[Power Source] 2 x AAA battery (Alkaline: 3.0V / Ni-MH: 2.4V)
[Power Source] (*1) Alkaline: 15 hours / Mi-MH: 12 hours (*2)
[Construction] Aluminum alloy (case)
[Dimensions (WxHxD)] 54.4 x 39.5 x 53.3mm / 2.1 x 1.6 x 2.1 inches (without cable)
[Weight] 154g / 5.4oz.
(Housing(s) compatible with Optical YS Converter/N1): MDX-D7100
* Optical YS Converters cannot be used with SEA&SEA housings not designed to incorporate them. Most, if not all SEA&SEA RDX and MDX series housings produced in the future will be compatible with an Optical YS Converter.

*1 Operating time depends on the battery brand, temperature and frequency of use.
*2 Operating time tested on 750 mAh batteries.