Abstract: An improved transferset assembly for transferring fluids between a first container, such as a medicament vial and a second container, such as a syringe, which includes an integral polymeric transfer assembly having a tubular collar portion, a radial portion overlying the rim of the first container, an outer tubular portion and an inner tubular portion which is integrally joined to the outer tubular portion by a radial intermediate web portion, a piercing member telescopically received in the inner tubular portion having a piercing end to pierce the closure sealing the open end of the first container and a removable closure which seals the open ends of the outer and inner tubular portions of the transfer assembly.