ONE PARCHMENT. 10cm. ( 3.93" ) When you order a Mezuzah from us we will fill it with the right size parchment according to the Mezuzah size you ordered. PARCHMENTS ARE SOLD SEPERATELY. One parchment is required for each Mezuzah you order. If you don't buy it from us, buy it from your Rabbi. The Blessing you need to say when puting it on is: "BARUCH ATA HADOONAI ELOOHEYNO MELECH HA'OLAM ASHER KIDDESHANO BE'MITSVOTAV VE'TSIVANO AL KVIAT MEZUZAH."