This is a Unique old transit probably from the 1940-50s. POWR-KRAFT brand Level and Transit instrument with the original handbook. All metal construction. It is removable from the base for attachment to a tripod. It has a removable metal plum bob and string attached to the base. Top of case is plastic/bakelite /or fiberglass?? Good working contition. Some oxidation of the chrome by the handle at top.