Upper-Flex Queen and Upper-Flex King are options for our Solaire adjustable firmness mattress. When paired with our Saatva Adjustable Base Plus in the Upper-Flex option, it gives each sleeper the freedom to raise the head of the bed independently and raise the foot of bed in unison.
Shop the Saatva Adjustable Base Plus with the Upper-Flex option here: https://www.saatva.com/furniture/adjustable-base-plus
The split on an Upper-Flex measures 30'' down from the head.
NOTE: The Upper-Flex is different from split king, which is two separate twin XLs placed side by side. A split king or split Cal king Solaire gives each sleeper the freedom to raise the head and the foot of the mattress independently, making it our most customizable mattress.