This moisture trap is capable of absorbing 1 litre of water helping to combat condensation and damp caused musty odours. The crystals cause condensation to filter through into the container area below so can be emptied multiple times until the crystal are used up. There are refill bags available with 500g (link here) or 2.5kg (link here) options.

Crystals are an irritant and must be kept out of reach of children and pets.