Sentry Safe with Mounting Base. Heavy, all steel. Can sink into a floor or wall, then conceal with rug or painting. Also has interior bolt holes for simple mounting on top of a floor. Although this is heavy, the shallow depth makes this suitable for an in-wall installation too.
Comes with working combination and instructions for the combo and in-floor installation.
Serviced by my shop (cleaned, lubricated, adjusted). The movement is smooth and reliable.