The Respirator NBC S10 was designed and developed for the British MoD. Its advantages include improved levels of protection, communication, vision, comfort, compatibility and maintainability. For protection the S10 has a high-performance integrally molded reflex seal. The facepiece is available in four sizes and has a minimum of molding crevices which improves contamination efficiency. The facepiece is held on the head by a fixed buckle harness arrangement that allows the respirator to be repeatedly donned and removed in seconds. Primary communication is via a horn-type voice transmitter and there is also a secondary speech transmitter for use with communications equipment such as handsets, telephones and microphones. Vision is improved by the use of low profile coated polycarbonate lenses. A facepiece rib ensures a good interface with NBC protective clothing hoods. The filter canister can be worn on either the left or right of the facepiece.