The crystals start off as a solid mass, once they have been soaked in water a chemical reaction occurs, which turns the crystals into a gel like substance. The gel fills the sealed pockets within the boot & acts as a soft, cold cushioning layer against the horses leg.
Crystals, which have been soaked in water, transfer cold to the horses leg. The anatomical shape of the boot ensures there is even pressure applied, so that the gel filled pockets remain in contact with the horses leg throughout treatment.
Once treatment has been completed & the boots have dried out, the crystals will return to their previous solid state & require soaking for a further two hours before next use.