O-ring-sealed and shock-proof ABS plastic case is ideal for lab and plant use. Unit is water-resistant to three atmospheres. Tactile-feel, click switches provide a positive action. To assure accuracy an individually serial-numbered traceable certificate is provided from Control Company ISO 17025 calibration laboratory accredited by A2LA. It indicates traceability to standards provided by NIST (National Institute of standards and technology). as a chronograph, the unit displays time of day in hours, minutes, and seconds, AM/PM date, and day of the week. Also has a time-of-day alarm. Digits are 1/4-inch-high. Supplied complete with 2-year always-on battery and lanyard. Replacement battery cat. Number 350-18940.