The height is 9".
Here is the low profile version (6" height): sears.com/serta-19-sleeptrue-lp-box-spq/p-A038732495?sellerId=SEARS
NOTE: For Split Queen and King box springs, you must order 2 to complete set.
It's easier to view mattresses on Sears.com. You can find the height listed in the Specification section on Sears.com.
Box springs: sears.com/home-mattresses-accessories-box-springs-foundations/b-5000613?searsTab=true&excludeMarketplace=true
Select the size in the left hand column of search results.
Hope this helps!