This is an Ainsworth Brunton Pocket Transit which dates from about 1911-1912, based on the date of the last patent shown on the lid plus the “Other Patents Pending”.  It has the original tripod mount, milled slots in two corners to accept the tripod mount, and the vertical bar style needle, with an arrowhead at the north end.

The condition is very good.  There is a damaged area in the aluminum case next to the face which appears as a dark area in the top left quadrant in the closeup of the face. The hinges are a bit loose, and the needle requires an occasional shake to get moving. However the fact that this is clearly a transitional piece in the historic Ainsworth Brunton line makes up for these deficits.