It's not just third-party brands that make reusable K-Cups. Keurig also makes their own versions.
After all, who knows Keurig coffee makers better than Keurig.
But be careful when purchasing a Keurig brand reusable K-Cup, because they sell three different types:
The My K-Cup Universal is a four-piece assembly:
I can hear you asking the big question now:
"If Keurig makes their own reusable K-Cup and it's compatible with every Keurig coffee maker, why isn't it number 1?"
Primarily price.
The Keurig My K-Cup Universal (and their other Keurig 1.0 and Keurig 2.0-specific versions) all cost a lot more than the Delibru Reusable K-Cup.
Plus, Keurig doesn't sell compatible paper filters. You can buy them from other companies, but now you're using two different companies for one reusable K-Cup. It's almost always easier to go with the one company that does it all: Delibru.