Checkmaster Checkbook Calculator Checkbook calculator tracks and totals up to three separate accounts for you. Giving you a snapshot of your financial picture at any moment. Functions include Low Balance Warning, Password, Floating Decimal and Standard Calculator functions. with Vinyl Cover, $29.50 with Leather Bi-Fold Cover, $42.00 with Leather Tri-Fold Cover, $48.00 Leather Tri-Fold Cover The trifold cover has the calculator on top and accommodates single or duplicate checks on the bottom or middle.  In the middle there is a vinyl (removable insert) holder for credit cards and it slides into a pouch.  There are no openings cut into the middle section.  On the back of the top is a zippered pouch and on the back of the bottom section there is a slit (pocket).