It is an RGBW strip with a clock pin. The FastLED.h library can work with strings with a clock line. Every 28XX prototype in the library allows for a clock:
case WS2801: { static WS2801Controller<DATA_PIN, CLOCK_PIN> c; return addLeds(&c, data, nLedsOrOffset, nLedsIfOffset); }
case WS2803: { static WS2803Controller<DATA_PIN, CLOCK_PIN> c; return addLeds(&c, data, nLedsOrOffset, nLedsIfOffset); }
I've just never used one nor seen any used by anyone in these forums.
There is an "LEDs and Multiplexing" forum on this site where your question may get answered.