PIPEs - Capped Call Options

PIPEs have obviously been a lot more popular over the recent weeks, and I've noticed a lot of language around capped call options, but am having some trouble wrapping my head around them.

Let's say a company issues $100 of convertible debt at a strike price of $10, and purchases call options capped at $15 to help offset dilution. So instead of a net issuance of 10 shares upon conversion, it would be 6.7. I'm confused by what a capped call option means - what is "capped"? Is the issuer just purchasing call options to cover the difference in shares between the strike price and cap price?

Thanks very much!