A syringe includes a monolithic barrel (12) being divided into two bore portions a first bore portion (22) extending from the needle adapter partially towards the second axial end and a second bore portion (24) extending from the first bore portion to the second axial end wherein the first bore portion is circular in cross section and the second bore portion has a cross sectional shape that at least partially extends beyond the radius of the first bore portion. The syringe includes a plunger (14) sized to fit within and move along the longitudinal axis of the first bore portion. A plunger rod (16) extends along the longitudinal axis of the monolithic barrel the plunger rod including a first array of notches and/or protuberances (30) along at least a portion of its length. The syringe includes an insert (18) sized to fit wholly within the second bore portion the insert defining a bore through which the plunger rod extends and including a first finger (36) extending into the bore defined by the insert for in use engaging the first array of notches and/or protuberances on the plunger rod.