Because it has a rubber finish on the contact surface which clamps on the hoops.
It's like it's made for wood hoops, but it's also nice to keep your metal hoops undamaged.
I clamped it on the resonance side at "7 'o clock" near the bottom, with the flex-arm pointing diagonally upwards toward the center, with a AKG D112 basedrum mic. in it (which is a clunky, heavy mic.)
Played a few hours, looked at it the next day and the nor the clamp nor the flex arm moved an inch.
So it's good. Keeps the position. Looks very sexy too.
That's one less piece of clutter in front of your kit.
The flex-arm is long enough to reach the center of the biggest size basedrums, and bend inside the port.
In fact, if you use a 20" or less, you'd probably want to screw a shorter flex arm on it -if you just mike the center of the resonance batter from outside and don't reach inside via a port.
Shorter flex-arms are even better in holding their position, but: too short to bend inside the drum port.
It's all standard mic. threads on this thing, so no worries about attaching other, aftermarket microphone related flex-arms.
That variability to switch the flex-arms is the big advantage of these type of clamps.
