Abstract: A syringe adapter for use on multiple sized syringes comprising: a neck, where the neck is capable of connecting to a syringe; a flange positioned just below the neck; a base portion positioned abutting the flange positioned just below the flange; and a tapered sleeve below the flange. The syringe adaptor may further include a cap that inserts into the neck of the syringe adaptor during non-use. In one particular embodiment, the cap includes a top flat portion and a stem that goes into the neck. Also, the syringe adaptor may include a cover that fits over the tapered sleeve during non-use.