Like a traditional gouge, the reverse bent gouge chisels start with a flat profile, and go through to a deeper profile. The shaft is also bent, allowing the very unique profile and bevel of this chisel to be used in hard to reach spaces.
Number. 30 chisels feature a convex shape two shallow steps up from the flat profile of the Number. 10 chisel.
Chisel Number. 25's and 28's feature deeper gouge profiles still.