Mophie, the accessory maker best known for its iPhone battery cases, is being bought for at least $100 million by rival Zagg.

The two companies announced Tuesday that they have signed a definitive agreement that will see the company paid $100 million at deal closing, with possible additional money based on the company’s adjusted earnings between April 1, 2016, and March 31, 2017.

Zagg CEO Randy Hales said in a statement that the deal creates “numerous opportunities” to boost profits and revenues by combining the two companies’ strengths and distribution networks. Mophie CEO Daniel Huang and operating chief Shawn Dougherty will continue in their current roles, reporting to Hales. The deal, approved by both boards, should close later in the first quarter.

In addition to its JuicePack battery cases and external battery products, Hales noted on a conference call that Mophie has strong retail relationships in the U.S. and overseas as well as a portfolio of more than 140 U.S. and international patents.

“We are combining with a talented group of people,” Hales said. While agreeing with an analyst’s assessment that revenue for Mophie has flattened out at around $200 million, Hales said the company has some exciting prospects. “We believe we are coming in at just the right time,” he said, adding later that “it’s a growth business, headed in the right direction.”

While Mophie hit its stride with the battery cases, it got its start as a scrappy little maker of iPod accessories. At one Macworld Expo, it featured a whiteboard around its booth where convention-goers could suggest their own ideas, the best of which would be made into a product. The winner was an iPod Shuffle case that doubled as a beer opener.

Though the accessory business can be a tough one, it has also attracted some big names due to its high profile and shelf space within electronics stores. Back in 2014, luggage maker Samsonite paid $85 million to buy Speck Products.