Set of three by crown tools

The three shapes are useful for different surfaces:

Rectangular scraper — flat boards, tabletops, panels, and straight edges.

Gooseneck scraper — the curved one at upper left; excellent for concave/convex curves, chair parts, mouldings, bowls, etc.

Curved/concave scraper — the long one in the package; useful for hollows and gently curved work.

They aren't meant to be used like ordinary blaades straight from the packet. The edge is prepared and then a tiny hook/burr is turned with a burnisher. Held slightly angled and flexed with your thumbs, that burr produces very fine shavings. A properly prepared scraper should make shavings rather than dust.

They're particularly good for smoothing difficult or figured grain where a hand plane might tear the wood, and they can often leave a surface that needs little or no sanding.