Weighted food grade magnets

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These are generally intended for use in sous vide cooking. However, they look like they would work well to weigh down hop sacks.

Note that this is for a total of 4, other count options are available.

4 Pcs Sous Vide Weights Magnets | Prevent Floating Sous Vide Bags | Food Grade Silicone Magnet | Better Than Clips, Racks and Other Sous Vide Accessories – note that multiple variations of this product may be available, as such a different version may appear at this link