Quick answer: A self-cleaning slicker brush has retractable pins — press a button and the pins retract, pushing collected fur off the brush in one motion with no manual picking required.
The brush head contains fine metal pins mounted on a retractable pad. Pressing the button on the handle retracts the pad, which pushes the fur off the pins as a clump ready for disposal. No picking hair out manually between strokes or after sessions.
Pin density (more pins are more effective for thick coats), pin length (longer for thick or long coats, shorter for fine or short coats), handle comfort for extended grooming sessions, and how completely the self-clean mechanism removes fur — some leave residual hair that still needs manual removal.
Slicker brushes work well for medium to long coats and double coats. For very short-haired breeds (Boxers, Greyhounds), a rubber curry brush is more effective and more comfortable. Check that pin tips are rounded or coated if your dog has sensitive skin.
The self-cleaning mechanism is a genuine quality-of-life improvement over standard slicker brushes. Worth the slight price premium — it makes regular brushing sessions faster and less frustrating.