Specifications include, but are not limited to: This respiratory breathing apparatus shall be a, self‐contained breathing apparatus (SCBA) consisting of the following major components: (1) a cylinder and valve assembly for storing breathing air under pressure; (2) a full facepiece assembly; 3) a removable positive pressure breathing regulator 4) a backframe and harness assembly for supporting the equipment on the body of the wearer. Cylinder and Valve Assembly The SCBA shall 4500 psig cylinder valve assembly and a duration of 30‐minute, 45‐minute or 60‐ minutes as rated by NIOSH. The SCBA shall maintain all NIOSH standards. The cylinder valve outlet shall be the Compressed Gas Association (CGA) standard threaded connection. Facepiece Assembly The full facepiece assembly shall fit persons of varying facial shapes and sizes with minimal visual interference. It shall be available in small, medium and large sizes and maintain NIOSH/MSHA certification of the apparatus regardless of the size used. Harness and Backframe Assembly A lightweight, adjustable, style harness and backframe assembly shall be used to carry the cylinder and valve assembly. The cylinder and valve assembly shall be positioned on the backframe. Pressure Guage The self‐contained breathing apparatus shall be equipped with a 4500 psig pressure gauge to monitor cylinder pressure.