Features include minimum/maximum memory and RH and temperature alarm. Unit measures 4 1/4" x 2 3/4" x 3/4" and weighs 4 ounces. Monitors are provided with an individually serial numbered Traceable certificate from an ISO 17025 calibration laboratory accredited by A2LA. Certificate indicates traceability to standards provided by NIST.. It is ideal for routine measurements. Monitoring round-the-clock. All quality-control needs. . . Thomas 4155 EZBio Traceable RH/Temperature Meter with Alarm Monitor Ambient Sensorm, 4-1/4" Height, 2-3/4" Width, 3/4" Length. Country of Origin : China. Part Number : 1170C18EA. Pack of : 1.