The M-nub is designed to be the perfect partner to the R-hop and ER-hop respectively. The M-nub is a nub, or hop packing to use the archaic term, designed to provide soft even pressure on hop buckings in virtually ALL PLATFORMS WHICH USE A STANDARD CHAMBER PACKING. It can function well with standard hops and flat-hop style hops, but was designed to be the premium packing for use with all R-hop variants. It is highly thermally stable, allowing complete functionality when paired with the IR-hop, and adhesive backed so unlike conventional hops it won't be constantly falling out of your hop chamber. Most importantly though it has very low lateral expansion for its vertical deformation. In English this means that, unlike a conventional rubber nub which has to squish outward in order to be compressed vertically, this doesn't. This means that when its boxed in, trapped in your hop chamber on all sides and under your hop arm, IT STILL BEHAVES AS A SOFT NUB which is unlike many other nubs/rubbers users substitute which may feel soft but have a fixed volume. Don't let appearances deceive you, it also produces exceptional concavity, despite its visually flat surface. Installation is straightforward, although there is an in-depth manual. NOW IMPROVED!