100 x Mushroom spawn substrate growing bags heat sealable high temperature Polypropylene bag. 20cm x 12cm x 45cm (7.8" x 4.7" x 17.1") sized bags are suitable for 2.5kg / 4.1L of substrate of choice. High quality heavy gauge 0.06mm substrate bags with 0.02 micron filter patch allowing air to pass in but not bacteria.
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