You are looking at a pre-owned Rockshox SID SL Dual Air fork for use with 26" wheels.
I've owned this since 2005 and it's been on the wife's "around the park" bike for past few years. Before removal, I rode around on her bike and it still seemed to function properly and the lock out still worked.
It's got scratches and some chips but, overall not in too bad condition.
Steerer tube approx 7 7/8"
Check out the photo, actual item.
Questions gladly answered, more photos gladly sent

Shipped Priority Mail

Thanks for looking!