The Envoy Data series of rechargeable SRAM PC Cards are capable of storing and retrieving large amounts of data with high speed and endurance. All SRAM cards are low power design and feature a write protect switch for data protection. Each SRAM card has a built in rechargeable lithium battery to insure data integrity so there is no need to replace batteries. When the SRAM card is in a PC Card drive slot the system supplies the power. The integrated battery supplies the power when the card is not in a PC Card slot.