These stoppers guarantee perfect sealing even with poorly finished rims on glass or plastic bottles. The top of the stopper has a septum which can be punctured by a hypodermic needle. Very secure fit prevents accidental opening of the flask.
POA means "Price On Application". Items displaying POA instead of the sell price do so for a number of reasons, not least because we anticipate some additional information is required in order to supply the most suitable options/configuration to each individual customer.