Special 510(k) is for modifying your own already-cleared device; Abbreviated 510(k) is for any device (yours or not) that can lean on a recognized standard or guidance instead of full predicate testing.
They solve different problems and aren't interchangeable. A Special 510(k) is only available when you're changing your own device and can verify the change through design controls, with review often as fast as 30 days. An Abbreviated 510(k) is available on a brand-new device too, as long as FDA has a relevant guidance document, special control, or consensus standard to lean on — it saves you from generating certain evidence from scratch, but doesn't guarantee the faster Special 510(k) timeline.
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