Durable & Tear Resistant – Our Mushroom Substrate Ready bags are designed with a side gusset to increase strength and durability (up to 5 lbs) Durable & Tear Extra Large Design – Our large grow bags are 8x5x20 inches. Plenty of space for your largest mushroom growing needsesistant – Our Mushroom Substrate Ready bags are designed with a side gusset to increase strength and durability (up to 5 lbs) High Quality – Our Mycology SUpplies bring you everything you need to succeed in your new hobby Excellent Filtration – 0.2 Micron filter and ventilation window for easy exchange of gases in our mushroom grow bags with filter Great Value – 50 pack at an affordable price for all your mushroom growing supplies