Apple is expected to announce a larger iPad Pro later this year, and rumor has it the new device could come with a stylus. Now a report from Business Insider reveals that the Cupertino company has been testing different stylus designs for years.

According to an anonymous engineer who used to work at Apple, the company had at least three prototypes in development roughly four years ago. The source says he or she never actually saw the styluses, but knew people involved with the project. The same insider also notes that a larger iPad was in testing at the same time.

It’s unclear exactly what happened to these stylus prototypes, though it sounds like Apple decided to cancel development or put it on hold. “The people that worked on it never learned why none of them ended up in production,” the source told BI. “They were told to work on something and then it was taken away and they didn’t have any idea.”

Of course, just because Apple tested a few different stylus designs back in 2012, that doesn’t prove it will release one now. However, it does suggest that the company has been kicking around the idea for a while. Cupertino typically waits until October to reveal its new iPads, so we may finally find out what happened to those stylus prototypes in just a few more months.