A sterile device intended to be attached to equipment during a medical/surgical procedure and/or to a needle during drug preparation (i.e., vial venting) to prevent the transfer of microbes, particulates and aerosols while allowing passage of air/gas; its use is not dedicated to a specific type of medical equipment. It is a small plastic housing containing a hydrophobic filter with male and female Luer connections (Luer-lock or Luer-slip). This is a single-use device.