Determining SSD Slot Sizes (Legion Pro 5i Gen 9)

I've got a Legion Pro 5i Gen 9. It currently contains 1 SSD, a 2280.

I want to put another SSD in. Obviously I want to buy one that fits. The hardware maintenance manual is pretty unhelpful here, it lists options for both the left and right SSD slots potentially being either 2280 or 2242 "depending on model". It also says nothing at all about single vs double sided.

How do I make sure I order the right drive without opening the device up first?