There are several items that are essential when putting together a save-a-dive kit, cylinder valve O-rings, fin straps, buckles, etc. One of the most important items is the spare regulator mouthpiece. This standard black silicone mouthpiece is universal and will fit a large variety of regulators out there. Mouthpiece is soft and comfortable. Don't let a bad mouthpiece be the cause of a leaking regulator always carries a spare. Oh Yea! Don't forget the tie wraps to attach it with! See: SKU AQUTW10 Tie Wrap.