It is also the whitest of the lights. The 50-watt lamp is ideally suited for the most serious photographers and videographers who demand the brightest light available. It is also the de facto choice for divers who shoot motion picture film underwater. G indicates a Goodman Handle. MR indicates MR-11 style head.
V indicates video reflector.
W indicates Sartek's exclusive locking wetmate connection system. I have heard there are problems with wetmates. Sartek has developed an exclusive locking system which maintains a secure connection. This system can also be used to fasten the two ends of the cord together so that the light head can be unplugged without fear of accidental loss. All Sartek HID lights can operate out of the water with no danger because they are gas discharge lights, which produce a lot of visible light and very little heat.