3 memory locations will let you monitor several accounts at one time: Savings Check and ATM transactions. You can also keep track of a personal budget or income and expense records in in one of the 3 independent memories. Solar Powered so it will work anywhere anytime. Built-in long life lithium battery maintains your memory files. Soft black leatherette wallet holds the checkbook calculator plus your checks bank receipts credit cards and more. Lock mode lets you set a password in order to protect your data from unauthorized access. Auto Shut Off function will shut the unit off automatically after 6 minutes if you forget to. Extra-large LCD Display is.6 inches high with large ease to read numbers. Large soft-touch rubberized keys makes the unit easy and pleasurable to use. Compact and lightweight (only 3.7 oz.): the Datexx Checkbook Calculator fits easily in pocket purse or briefcase. Dimensions: 6.5 L x 3.75 W x 0.3 D.