Variation: Parking Validation Stamp Books - One Validation Period Sold in: Packs of 10 books (Total 1,000 stamps per pack). Ink: Color ink on one side - available in 2 colors Numbering: Each book of 100 stamps is numbered with all the same number Security: The security "X" slits on each stamp provide a self-destruct tamper-proof security feature. The self-destruction is accomplished by our permanent adhesive and the "X" shaped die slit within each stamp to make it very difficult to peel off the stamp once applied. Any attempt of removal will self-destruct into many pieces. Put up: Each book is glued on the left and contains 10 sheets of stamps and a chipboard backing (100 stamps per booklet).