A device including a catheter (14) and a medical instrument (12). The catheter includes an inner portion (16) and one or more unlocking features (18). The medical instrument includes one or more locking features (24). When the medical instrument is in the inner portion of the catheter, the one or more unlocking features engage the one or more locking features so that the medical instrument can bend in the catheter. When the medical instrument is outside the catheter, the one or more unlocking features disengage from the one or more locking features so that the medical instrument is restricted from bending.
