20 Pack of 25 X 50cm Grow Bags allow plenty of room for mushroom growing and spawn, substrate and fruiting. These side-gusseted breathable bags stand up and hold strong. TEAR RESISTANT: Extra Thick 6 Mil Bags, these are designed to withstand high temperatures come with sterilization.High temperature resistance 121-125 Celsius FILTERING 2 Micrometre filter allows for gas to freely be exchanged, while keeping contaminates out. The clear bag helps to quickly spot any instances of contamination GROW LIKE mushroom growers around the globe these bags to dramatically reduce space needed to grow or spawn mushrooms when compared to trays, tubs MULTI for inoculation of media with mushroom oyster spawn, clone oyster mushrooms and more specification: Thickness: Extra Thick 6 Mil Bags Sealing :Our these mushroom bags can be sealed with an impulse sealer, or just tie to seal . these bags are durable and can be reusable in . Water content of material: If the water content of the medium is too high, the ventilation will be affected, hyphae will grow slowly due to lack of oxygen, moisture will be deposited in the lower half of the cultivation bag, and the hypha length will not be able to go. Colour: transparent color Material: PP Size: 25x50cm Package Contents: 20 x Mushroom Grow Bag Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.