A catheter with an improved retaining, activation and locking features is provided which is a safe device with reduced irritation and discomfort for a patient. The retaining mechanism positioned at the proximal end of the catheter assumes a “closed” position for introduction and removal of the catheter into and from the body cavity of a patient, and is transitioned into the “open” position when the catheter is positioned within the body cavity by mechanically manipulating the retaining mechanism through an activation mechanism having a piston member slideably displaceable within a cylinder housing member. A locking mechanism is included for maintaining the catheter in the “open” position.
