A delivery system (114) for a self-expanding device (110) for placement in a bodily lumen, the system comprising a sheath (112) that confines the device to a radially compact delivery disposition until the device is to be released into the lumen, the system having an elongate pull element (118) to be pulled proximally from its proximal end, which pull element is arranged radially inside the sheath for pulling preferentially on a pull zone on the circumference of the distal end of the sheath, thereby to tear the sheath progressively along a tear line running the length of the sheath, starting at the distal end of the sheath, to release the device from the confining effect of the sheath, progressively, beginning at the distal end of the device and wherein the sheath is of polyethylene-terephthalate, cold drawn along its long axis, and in that the distal end of the sheath tapers inwardly to provide an inwardly tapered distal end of the system.
