I have tested this in diverse settings before reviewing. 
 
I use another rack clamp-not rotatable- that looks a lot like this one, on a 60 cm side wing piple, onto which a wide range of standard (boom) rods and stuff can be clamped. 
Such as modules, a side snare, cymbals, anything. 
 
The pipe itself is clamped onto the hi-hat stand with another heavy duty Gibraltar clamp with extra wide clamps. Just to be sure. 
 
If you're attaching a lot of weight onto a side wing pipe connected to your hi-hat stand or cymbal stand, it will fall over. 
So you need to secure them to another stand, and the non-rotatable rack clamps will do. 
Maybe use a 2nd pipe with their bomb proof pipe extension. 
Everything is secure now. 
 
So now, if you want to clamp anything else on your secured side wing that's *not* straight up vertical, that's where this rotatable clamp comes comes in. You can adjust any stand/rod in as much angle as your space prohibits now. 
The angle option with the drum key adjustion works beautifully, and the angle option makes it really multi-usable, as advertized. 
 
For stabilizing any stands -with a lot of weight attached to it- I could also use cheaper options such as an extension (stabilizer) pole with 2 clamps on each side, but this solution is really much more versatile and flexible. 
 But let it be said: the moment you start gigging with these clamps, you will experience the need of covering in any way them during transport in a hardware bag
Otherwise the shiny chrome will splinter off fairly quick.
That’s why I transport them in a mic. bag with dedicated sleeves in it.