You will receive 10 books. They are 2 Part Carbon-less Sales Order Books Receipt Form Invoice 50 Set new. It is 5 9/16"x 8 7/16"Attention buyer Based on new USPS rate changes: Shipment and payment: Shipments weighing less than 16 ounces will be shipped via First Class USPS Mail. All shipments over 16 ounces, we will always fit what we can into a Priority Mail Flat Rate Envelope or box whenever possible. Also, Insurance coverage is included on our all Priority Mail packages. Shipping prices include an 11% fee that collects on all shipping costs. In order to get the great combined shipping discount, you have to pay everything in a single PayPal transaction. The following 2 options are available : Option 1- Please add all items to your shopping cart then check out at once in order to pay for all items in a single PayPal transaction. option 2-Use Buy It Now option, commit to buy all items. After you are done shopping, Please send me a request for combined invoice (BEFORE YOU PAY) and wait for an invoice from us with combined shipping. Attention to my entire Dear customer: If for any reason you put your items in a shopping cart and shipping cost seems high to you, Please email me all the items number and the quantity you wish. Ask me for a special listing . I will do that for you to make sure you will charge correct shipping cost.It seems there is a problem which combined invoice does not work properly.