The first two characters in a VIN with 13 symbols or the first three characters in a VIN with 17 symbols are the factory code. Individuals can recognize a VIN by checking for a sticker with a print that says “Manufactured by John Deere.” Tractors built in the 1960s and 1970s typically contain around five to six letters and numbers only, although machines manufactured at a later period contain 13 to 17 letters and numbers. John Deere 100 Series tractors usually have a serial number on the frame close to the back left wheel, whereas zero-turn mowers have a serial number below the seat, atop the frame on the right section. The serial number, also called vehicle identification number, of steel-deck, walk-behind John Deere mowers is typically found on the left area of the mower deck.