The CK60 Series: CK61 B utilizes a magnesium top cover and tough rubber bumpers at each corner to achieve extremely rugged environmental specifications. The case is sealed against water and dust to IP64 standards to ensure years of trouble-free service. Onboard non-volatile memory called Persistent Storage, preserves applications and databases even if the batteries become depleted. The CK60 Series: CK61 B is available with either Microsoft Windows CE or Microsoft Windows Mobile software for Pocket PC. Microsoft Windows CE provides significant flexibility to those customers who wish to control the user experience; Windows Mobile offers a standard platform which can easily be applied across the enterprise. Most models have high-speed Ethernet, USB Host and Client, and RS232 serial connections and a WiFi-certified 802.11b/g radio for local area wireless communications.