Schumacher has releases a new lightweight more durable front spool for the Mi5evo. One of the main features is that the spool has steel outputs rather than the slider-type interface included in the original kit. These will provide a longer life platform with less expense replacing sliders and not forgetting the lower weight.
Secondly there are these super strong steel gear diff outputs. Replacing the slider interface makes for a more cost effective, more durable drive system.

Source: Schumacher