OnePlus is taking aim at its rivals...by making an iPhone case?

OnePlus's new Sandstone Case fits on iPhone 6 or 6s, adding the company's sandstone finish, which is designed to make a device less slippery and thus less likely to suffer a spill, to Apple's smartphone.

More notable, however, is that the purchase of this $19.99 case comes with an invite to purchase the OnePlus X, the company's new midrange device. OnePlus also teases the possibility of a free phone for select buyers.

Since its inception, OnePlus has sold phones via a sometimes complex invite system, so it's been hard to get your hands on one. But you can now effectively buy an invite for $20.

Unfortunately, that invite is for the OnePlus X rather than the OnePlus 2. In PCMag's review, the X lost points for missing North American LTE bands and an aging processor. But we found that the OnePlus 2 offers unbeatable unlocked smartphone value, delivering top-end performance and features at a fraction of the cost of competitors.

"It's not just about a case. For us and for many of you, Sandstone represents something bigger," OnePlus wrote in a blog post on Tuesday. "Maybe you know someone who just went out and bought the latest iPhone. Maybe you were this close to getting them to see your side of things. This is your chance to leave your exasperation at the door and just show them what they're missing."