Semi-rigid probes can be built with a special metal alloy that will hold its shape.
The shape is put into the tube using a heating process. The scope can be straightened with an outer sheath, and then deployed by retracting the sheath, or it can be used without the sheath. This type of scope is not advisable for general use where the shape memory properties are not needed because the tubing is more expensive and has a thicker wall which limits lighting possibilities. A scope of this type can replace a much more expensive and fragile articulating scope.
Conventional semi-rigid scopes can also be permanently bent into shapes specified by the customer. These scopes will remain bent and will not straighten or deflect like shape memory probes will.