A transurethral catheter kit comprises a catheter (2) and a syringe assembly (3), the catheter having a distal end (4) and a proximal end (5), an inflatable balloon (6) disposed on the distal end, an inflation lumen having a proximal portion adapted to establish fluid communication with the syringe assembly (3) and a distal end in fluid communication with the balloon, and a drainage lumen adapted to drain fluid from the bladder during use. The syringe assembly comprises a syringe and a nozzle (11), the nozzle comprising a pressure relief valve (9) adapted to exhaust fluid from the syringe assembly when the pressure in the fluid reaches a threshold pressure. The nozzle additionally comprises a narrow bore (12) of 0.04mm2 to 0.06mm2 cross sectional area disposed in the nozzle proximally of the pressure relief valve.
