Perfect "detent", perfect centering, perfect fit and finish, an awesome button lock especially for the price.

Pros: Centered, sharp, snappy (stiff "detent" on my example), no button stick, grippy micarta. Con(s): theres not nearly enough (none, really) relief cut into the scales/liners to allow even a medium sized thumb to get behind the thumbstuds. If you've got a weak detent this might not be a problem, but a strong one guarantees sore thumbs (or worn down thumbnails). If you're partial to thumbstud deployment, the Sachse is a better choice... YMMV