My daughter's Sora shifters have a reach adjustment built in. It has far more adjusment than the Specialized Slim Shims I put on my Ultegra levers.
Specialized shims are the only ones available for Shimano levers, as far as I know. They do not offer them for Sora shifters, which would make sense because (if) the soras still have built in adjustment, they wouldn't be needed. Maybe the poster who received them with Sora shifters got some other type?
Here's the page which lists the specialized shims.
http://www.specialized.com/us/en/bc/...Levers&eid=367