What is it?

1234567891011
Across
  1. 2. 6666
  2. 6. 8888
  3. 7. 1111
  4. 8. 1010
  5. 10. 1212
  6. 11. 5555
Down
  1. 1. 9999
  2. 2. 7777
  3. 3. 11
  4. 4. 4444
  5. 5. 3333
  6. 9. 2222