concave slope in open pit

concave-concave

concave downward‘ concave down

concave-up concave-down

plane-concave lens (=plano-concave lens)

Pit-in-pit

“concave” type

0-diagonally concave relation

Abney mounting for concave grating

absolutely concave function

An are equi-uniformly u0-concave operators

annular concave spherical surface

belt conveyor + concave segment + curvature radius

bi-row concave ridge

blade with concave surface

central concave abrasive

characteristic concave or convex of surface

Circular concave sound source

cold extrusion concave die