Cart Shopping Cart My Store Account Orders Downloads Shopping Cart “507. Balance Computer Type Slide Rule” has been added to your cart. Continue Shopping Remove item Thumbnail image Product Price Quantity Subtotal × 507. Balance Computer Type Slide Rule $20.00 507. Balance Computer Type Slide Rule quantity $20.00 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $20.00 Tax $0.00 Total $20.00 Proceed to checkout