I also know about these bottles cause I have received Apistos for more than two days of travel and the fish were still in perfect condition! There is no need to put O2 in it to keep the fish alive. It is like the onces used to sample urine in hospitals. The size of the bottle is 2" in diameter and around 3-4" in height. Edison ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!