Apple on Wednesday said it will have ‘limited’ numbers of its folding iPhone Duo phone available for walk-in customers when the device launches on Friday, after initial online orders sold out in minutes and pushed delivery times for some customers to January.

Apple announced its first folding phone in September, with analysts expecting it to quickly come to dominate a niche segment where rivals such as Samsung Electronics and Huawei Technologies have sold premium offerings for years.

But the iPhone Duo is also a more complex product than standard candy-bar iPhones, with a tight-fitting hinge that analysts believe may take time for Apple to learn to manufacture in high volumes.

“On Friday morning, our teams look forward to welcoming customers at Apple Stores to experience iPhone Duo and the incredible iPhone line-up for themselves,” Apple said in a statement.

“Apple Stores will have limited iPhone Duo available for walk-in customers, and we’re working hard to get this revolutionary new product into customers’ hands as quickly as possible,” it said.

The availability of walk-in units will vary by country, Apple said.

Online order pickup and limited walk-in purchases will be available in the United States, Australia, Canada, Mexico and much of the UK and Europe.

Other regions will only have iPhone Duo units available for customers who already bought them online, including mainland China, France, Hong Kong, India, Japan, Malaysia, South Korea, Taiwan, Thailand and the UAE, Apple said.

On the China-governed island of Macau, the iPhone Duo will be available for walk-in customers only, with limited inventory, Apple said.