Yes. The 1-2-3 Variflow teat should have a small slit in it. The spontaneous opening of the little slit is sometimes confused with the teat having torn. If you can only see 2 little holes, the silicone material may still be stuck together with it being new. You can separate the silicone material by squeezing tightly on the top of the bottle teat or by rolling it between your thumb and index finger. This will release the silicone and allow the teat to work as normal. Another way to do it is by turning the teat inside out (and then back again). The slit can be opened manually at any time.
1-2-3 Variflow teat user guide (pdf) >
1-2-3 Variflow ring user guide (pdf) >