All grades of Constable perform the same basic range of duties, with the rank only reflecting experience. The rank of Probationary Constable is held for the first fifteen months of service. A Constable with one stripe is qualified for promotion to Senior Constable. A Senior Constable First Class is either an officer qualified for promotion to Sergeant/Senior Sergeant or has won a Senior Constable First Class position on merit. A Brevet Sergeant is a temporary designation for an officer in a particular position which would require specialised skills, such as a Detective,