A female connector for medical infusion systems has a main body that has two curved wings that extend from the outer circumferential surface of the body. The respective front ends of the wings are joined integrally to a substantially circumferential partition that also extends circumferentially from the outer circumferential surface of the fitting. The connector of the fitting has a non-conventional configuration with at least two protuberances offset at an angle. The non-conventional configuration of the connector allows the fitting to only mate with a counterpart connector that has a complementary non-conventional configuration.