Improvements in preventing heat- and moisture-shrink problems in specific polypropylene tape fibers are provided. The split ring first half and second half having an inner surface configured to mate with an exterior of the waveguide, the first half and the second half foldable towards each other and around the exterior of the waveguide, along the web portion. Still furthermore, the present invention discloses a method of providing a perforating gun string having multiple guns, each gun selectively detonated at a corresponding well zone, and the gun string being stored in a lubricator at the surface between alternating sequences of perforating and treating the well zones. The electric vehicle is also provided with a friction brake system for applying vehicle braking through frictional force.