Ruber or Rubber: How To spell?
The word Ruber is misspelled against Rubber, a noun meaning "A coarse file, or the rough part of a file."
Rubber has double "bb" is mispronounced as "b"Remember double 'BB' in between the strings Ru & er which should not be misspelled with single 'B'
Wrong Spelling:  Ru-b-er  Correct Spelling:  Ru-bb-er 
Check more misspelled words of Rubber to spell it correct.