The buckets come with plastic lids that have holes drilled into ideas to include an airlock or blow off tube--these kits usually come with tubing and airlocks.
They are constantly exposed to use and tear when they are acustomed properly. http://bir.Localmesh.org/doku.php?id=ab_doe_twist_eviews_-_o_whethe_a_pe_son_get_an_ab_doe_twist