The CK60 Series:CK61 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 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.