An endoscopic stone-extraction device is provided comprising a support filament comprising an end portion, a sheath comprising a lumen, wherein the support filament is disposed in the lumen such that the sheath is slideable with respect to the support filament, and a handle comprising an actuator. Movement of the actuator in a first direction retracts the sheath and causes a shape to expand outside the lumen. Movement of the actuator in a second direction advances the sheath and causes the shape to at least partially collapse inside the lumen. Other embodiments are provided, and any of these embodiments can be used alone or in combination.