It looks like a combination of the old on-deck donut and the old sleeve weight, rubberized, endorsed and marketed at higher price point.
Bat weights have been around forever, great to stretch with on-deck. As with any weight addition or subtraction, excess use has the potential to break rhythym and can affect reaction timing.
Suggest to use caution with bat weights, as they can and have taken off $300 bat knobs. All welds are not created equally.