it needs a stopper on both ends [SEP] my month old loves this and will chew on it for a long time i really like the stopper so she cannot gag on it however if she grabs it and puts the wrong end in her mouth i find she can gag herself quickly because that end can go really far into her mouth i have to watch her constantly while she is chewing on this or she will have it turned around and gagging on it in no time