There are 20 pieces. There are some minor scratches. For combined purchases, you can get 100 yen off for each additional item. The ruler has markings of 2mm each. Thank you! ^ ^ #cabochon #decoration #parts #decopa #tradingcardcase #cute #handmade #materials #smartphonecase #accessories #crafts #materials #nailparts #elementaryschool #dollhouse #interior