I’ve used other plunger-and-sleeve style adjustable measuring cups, and they were great for measuring odd quantities or volumes without using several different-sized cups (or one size several times), but sticky or oily stuff got in between the plunger and the sleeve, making reuse impossible without stopping to disassemble and clean the cup.
OXO has taken a page from the AeroPress coffee maker and solved this problem by using a similar gasket on the end of the plunger that seals against the sleeve and pushes the measured item out. The plunger rides in helical grooves in the sleeve, so one twists to adjust the measurement or eject the measured item. This makes additive measurements of a second item easy and allows more controlled ejection, too.
The grooves stop short of the extent that would allow you to pull the plunger from the bottom of the sleeve, ensuring that the gasket wipes the sleeve. End result: the only part you usually wash is the gasket itself.
The sleeve is marked in multiple units, with one set for liquid measure and one set for dry; the latter assumes some empty space at the top, great for coarse items, lightweight flours — and shaky hands.
These fulfill OXO’s stated mission of not just reproducing tools, but finding ways of improving the functionality by a noticeable amount. -- Pierce Presley