Poly tube grow bags perfect for growing mushrooms on straw. 
 
These bags are not heat resistant and are not to be used in boilers, steamers or pressure cookers. They are for adding substrate into after it is cooled and drained. Click here for high temp mushroom bags. 
 
These bags are 30cm wide (when laid flat) by 65cm long. When packed with straw they end up approx 22cm wide.