A pierceable cap may be used for containing sample specimens during storage and transport. The pierceable cap may prevent unwanted escape of sample specimen before transfer with a transfer device. The pierceable cap may fit over a vessel. An access port in the pierceable cap may allow passage of a tip of a transfer device though the pierceable cap. A frangible layer may be disposed across the access port. One or more extensions proximate to the frangible layer may be coupled to the pierceable cap by coupling regions or other similar devices. The one or more extension may rotate around the one or more coupling regions during insertion of the transfer device. The movement of the one or more extensions may pierce the frangible layer to create airways and allow air to escape from a vessel at a reduced velocity.