OnePlus has been considered a much more affordable smartphone than the iPhone. Now, the company decided to create a case for the iPhone 6 and iPhone 6s, but there is a catch.

OnePlus is trying to lure some iPhone 6 and iPhone 6s owners to switch over to the OnePlus X. OnePlus is selling an iPhone 6 and iPhone 6s case that will include an invitation to purchase the OnePlus X, Engadget reports.

The point of offering the iPhone case is not to help iPhone owners protect their phone but to show them what they are missing from OnePlus.

The Sandstone case offers a strong grip and it feels sturdy and heavy duty. Most of the cases available for iPhones are made of silicon.

OnePlus explained why they created an iPhone case in a blog post. They said that giving iPhone owners the feel of OnePlus will show them "what they are missing."

The $19.99 case will come with an invite to purchase the OnePlus X smartphone. Some lucky buyers of the case will get an invite to buy the rare ceramic version of the OnePlus X and a few will even get the smartphone for free with their invite.

The OnePlus X starts at $249, much cheaper than the $649 iPhone 6s. The OnePlus X can't quite compare to the premium features of the iPhone 6s, but it is still a very powerful smartphone for a great price.

OnePlus' co-founder Carl Pei is trying to tempt iPhone owners to see what it feels like to hold a OnePlus X by using the same Sandstone texture on the iPhone case that it uses on the OnePlus X.

The Sandstone case that OnePlus has built for the iPhone 6 and the iPhone 6s will sell for $19.99. Right now, the case is sold out on OnePlus' website, but more should be coming soon.