We’re just days away from the launch of the Apple iPhone XS and iPhone XS Max. Beforehand, regulatory filings in China have revealed two of the final unknowns about the handsets, the size of the batteries and internal RAM. The documents, which also include information on the iPhone XR, were first published by China’s MyDrivers website.

According to documents from China’s Ministry of Industry and Information Technology (TENAA), the 5.8-inch iPhone XS has a smaller battery than its predecessor, the iPhone X, 2,658mAh versus 2,716mAH. Despite this, Apple claims the iPhone XS can last up to 30 minutes more between charges than the older model.

Documents show the 6.5-inch iPhone XS Max has a battery with a capability of 3,174mAH. Apple says the new phone should last 90 minutes more between charges versus the iPhone X.

Meanwhile, TENAA says the 6.1-inch iPhone XR, which doesn’t arrive until late October, includes a 2,942mAh battery. Apple promises 90 more minutes of usage between charges versus the iPhone 8.

The Chinese documents also show the iPhone XS and iPhone XS Max both include 4GB of RAM, while the iPhone XR has 3GB. Last year’s iPhone X had 3GB of memory, while the iPhone 8 had 2GB.

Until third-party testing, it’s difficult to determine what these battery capabilities mean for end-users. Plus, it often takes software updates to fully realize the battery improvements from one generation device to the next.

The iPhone XS and iPhone XS Max officially arrive in stores on Friday, Sept. 21 with pre-orders ongoing. Pre-orders for the iPhone XR begin on Friday, Oct. 19 in many locations with sales starting one week later on Friday, Oct. 26.

Are you buying an iPhone this year? Which model did you decide to buy?