A controller (10) for manually controlling a guidewire (50) includes a housing (100) including a passage (112) for receiving the guidewire. A gripper (140) is actuatable to grasp the guidewire (50) in the passage (112). A cap (200) is connected to the housing (100). The cap (200) is rotatable relative to the housing (100) to actuate the gripper (140). The housing (100) includes an element (160) for maintaining the cap (200) in a receiving position. The cap (200) when in the receiving position places the controller (10) in a condition for receiving the guidewire (50).