If you're like me and want your tremolo bar to move right out of the way when you are finished with it, rather than the hindrance of pushing it yourself, but also need the bar to be solid with little or no "give" in it when using it, this the bar you need.
As others have mentioned, not sure why this is not standard on an floyd rose style bridges - likely to make people buy their accessories.
As I've set mine to move right on the edge of moving freely, it does have the slightest bit of give in it, but its so tiny its not something you'll notice when playing, unlike the other bars which are massively off putting, so thats the main thing!!!
Cheap, easy upgrade for anyone, and well made. Its also very easy to adjust the tension of the arm. 100% recommended!!!