SEBCDM-01 SebArt Contra Drive System w/Hacker C50-12XL Competition Motor, Gearbox, Soft Mount, props and spinner - SebArt Airplanes

If anyone has first hand knowledge of this system could you send me a message? I'd like to know what the spinner diameter is and what the all up weight is of the system is.

Also, I think this system is relatively 'old'? Came out in 2013? Anything to be aware of? Does it take special props or prop adapters? Does it come with a manual and what's the maintenance consists of and the interval in between, etc.

thank you,
Lucky