Just like a flashlight, sometimes you have things on your key chain that you may need to quickly and easily detach. That might even be your actual keys! The Kappa QR delivers convenience (and security) in an entirely new way.
This design is identical to (and compatible with) the Beta-QR v2 quick release design. A proprietary "canted coil spring" is used to provide a "snap together" action: two pieces, no moving parts, nothing to break and the spring is replaceable if that's ever needed. The spring is manufactured by a company that specializes in only this type of spring. It's commonly used for electrical and mechanical interconnects on everything from heart implants to military electronics to stuff that flies in space. It should be adequate for your house key.
OPERATING NOTES: Twisting the two halves while connecting/disconnecting the QR will significantly reduce the amount of force required to connect/disconnect. This is the preferred method, though it is not strictly necessary. Just pretend like you are screwing (or unscrewing) the two halves...but there are no threads of course. The twisting action pre-loads the canted coil spring and makes it easier to compress.
BREAK IN PERIOD: The sharp edge of the retaining groove (male portion of the QR) can create an excessively crisp/sharp detach on a brand new QR. The first few dozen actuations will round-over this edge. Over time, the connect/disconnect should become smoother.