Twin XL and split king mattresses are similiar. Technically, a split king mattress is two twin XL mattresses pushed together for couple's comfort.
Queen vs. Twin XL: What's the Difference? - eachnight
Mattress Sizes Latex For Less
Tempur LuxeBreeze Firm - Twin XL
Twin XL vs. Split King
Official Split King vs Twin Size Comparison Guide
Lucid 12 Inch Split King Mattress and L600 Adjustable Bed Base – Plush Gel Memory Foam Mattress – Bamboo Charcoal – CertiPUR-US Certified – Easy Assembly : Home & Kitchen
Difference between king and queen size beds, queen and king size difference
Mattress Sizes and Bed Dimensions For Room Size Needs - eachnight
Full Vs. Queen: What's the Difference? - Healthy Americans
Split King Latex Mattress Guide For Couples (Pros + Cons Of Two Twin XLs)
Adjustable Bed Sizes and Dimensions Guide - Amerisleep
Split King Vs King Size Mattress: What Is The Difference?
GhostBed Split King Custom Adjustable Power Base 11 Inch Cooling Gel Memory Foam Mattress : Home & Kitchen
King vs. Split King: What's the Difference? - eachnight
The Difference Between a Queen and King Bed