From the manufacturer:
The crane has long been a symbol of peace and longevity. Folding one thousand cranes is an expression of hope, goodwill and promoting peace for all of mankind. As a gift, 1,000 cranes is a powerful gesture of caring, devotion and love. This kit includes everything needed to create a beautiful decoration or gift. It contains 51 sheets of 20 brilliant colors for a total of 1,020 sheets of 3" square origami papers. It also comes with a string for hanging, 30 decorative beads and instructions. The finished hanging project is approximately 36" long.