The name "memory lock" says it all. It's a memory clamp at first, but also serves as an extra security (lock) in most situations.
I use this for a Tama boom, but it's held by a Gibraltar clamp so it's the perfect combination.
They're also one of the better deals in memo lock-land.
The price difference between non-hinged and hinged memo locks in this price range are too insignificant to not choose for the latter, even if a non-hinged memo lock would do.
More flexibility.
In any situation where Gibraltar clamps are being used, it's best to use the same brand memo-locks because of their matching locking mechanism.