This is a new RB Concepts L2G Magnesium cooling head/heatsink.
Will fit any L2G designated RB engine.
Will also fit other Novarossi family engines that have the top part of the block that is "round". Certain P5 cases; etc. It sits about 2-3 fins lower in overall height compared to a traditional Nova heatsink.
It weighs considerably less than aluminum & lowers the overall CG. Finish is a matte-black.
$55 with Free shipping in the USA.