This system, if used properly, ensures that your fish line will never tie itself to the bowstring, which is the cause of deadly arrow snap-back! Slide sets for 5/16” fiberglass arrows will include a slide, “shock” pad, screw and nock and will be packaged in sets of 5. A nock is NOT included with sets for #2213 aluminum arrows. Several Key Features Include: Made of high impact glass filled material. It is tough; Splines on the inside of the slide eliminate dirt and sand problems; Urethane “shock” pad prevents impact damage to the slide; If the line is tied correctly, it will trail the arrow the arrow dead on center, offering near perfect arrow flight; Fish line is protected from abrasive fish scales by a molded grove on the exterior of the slide ;Use of the slide will also help prevent shooting through fish.