Hammond Manufacturing 1551KGY. 3.15" x 1.57" x 0.8" gray ABS plastic with interlocking lid. Integral standoffs for pc board mounting. Lid held in place with self-tapping #4 screws (included).
These are real tiny boxes. Make sure that you allow for the pc standoffs at the bottom of the box. You're left with about .5" of workable space after the standoffs.