The NBG 513 is a NEMA 12 notebook PC built for tough real-world jobs. It meets MIL-SPEC standards for high and low temperature, rain, humidity, salt, fog, sand, dust, altitude, shock, vibration, and EMI. This unit features an Intel Mobile Pentium III 850 MHz CPU and 128 MB of RAM, expandable to 512 MB. The included 20 GB hard drive can be upgraded to 40, 60, or 80 GB.